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Background: Bivalent freeze-dried neurotoxic (FN) antivenom has been the primary treatment since the 1980s for Taiwan cobra (Naja atra) envenomation in Taiwan. However, envenomation-related wound necrosis is a significant problem after cobra snakebites. In the present study, we analyzed the changes in serum venom concentration before and after antivenom administration to discover their clinical implications and the surgical treatment options for wound necrosis. Methods: The patients were divided into limb swelling and wound necrosis groups. The clinical outcome was that swelling started to subside 12 hours after antivenom treatment in the first group. Serum venom concentrations before and after using antivenoms were measured to assess the antivenom's ability to neutralize the circulating cobra venom. The venom levels in wound wet dressing gauzes, blister fluids, and debrided tissues were also investigated to determine their clinical significance. We also observed the evolutional changes of wound necrosis and chose a better wound debridement timing. Results: We prospectively enrolled 15 Taiwan cobra snakebite patients. Males accounted for most of this study population (n = 11, 73%). The wound necrosis group received more antivenom doses than the limb swelling group (4; IQR:2-6 vs 1; IQR:1-2, p = 0.05), and less records of serum venom concentrations changed before/after antivenom use (p = 0.0079). The necrotic wound site may release venom into circulation and cause more severe envenomation symptoms. Antivenom can efficiently diminish limb swelling in cobra bite patients. However, antivenom cannot reduce wound necrosis. Patients with early debridement of wound necrosis had a better limb outcome, while late or without debridement may have long-term hospital stay and distal limb morbidity. Conclusions: Antivenom can efficiently eliminate the circulating cobra venom in limb swelling patients without wound necrosis. Early debridement of the bite site wound and wet dressing management are suggestions for preventing extended tissue necrosis and hospital stay.
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Background: Bivalent freeze-dried neurotoxic (FN) antivenom has been the primary treatment since the 1980s for Taiwan cobra (Naja atra) envenomation in Taiwan. However, envenomation-related wound necrosis is a significant problem after cobra snakebites. In the present study, we analyzed the changes in serum venom concentration before and after antivenom administration to discover their clinical implications and the surgical treatment options for wound necrosis. Methods: The patients were divided into limb swelling and wound necrosis groups. The clinical outcome was that swelling started to subside 12 hours after antivenom treatment in the first group. Serum venom concentrations before and after using antivenoms were measured to assess the antivenom's ability to neutralize the circulating cobra venom. The venom levels in wound wet dressing gauzes, blister fluids, and debrided tissues were also investigated to determine their clinical significance. We also observed the evolutional changes of wound necrosis and chose a better wound debridement timing. Results: We prospectively enrolled 15 Taiwan cobra snakebite patients. Males accounted for most of this study population (n = 11, 73%). The wound necrosis group received more antivenom doses than the limb swelling group (4; IQR:2-6 vs 1; IQR:1-2, p = 0.05), and less records of serum venom concentrations changed before/after antivenom use (p = 0.0079). The necrotic wound site may release venom into circulation and cause more severe envenomation symptoms. Antivenom can efficiently diminish limb swelling in cobra bite patients. However, antivenom cannot reduce wound necrosis. Patients with early debridement of wound necrosis had a better limb outcome, while late or without debridement may have long-term hospital stay and distal limb morbidity. Conclusions: Antivenom can efficiently eliminate the circulating cobra venom in limb swelling patients without wound necrosis. Early debridement of the bite site wound and wet dressing management are suggestions for preventing extended tissue necrosis and hospital stay.(AU)
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Animais , Mordeduras de Serpentes/terapia , Agentes Neurotóxicos/efeitos adversos , Taiwan , Necrose/terapiaRESUMO
El manejo de la infección por SARS-CoV-2 en Taiwán ha sido catalogado como uno de los más eficientes del mundo. Tiene una población que es casi equivalente a la del Perú, pero el número de infectados fue menor de seiscientos y la mortalidad ha sido sumamente baja: solo siete pacientes han fallecido hasta el mes de diciembre. A pesar de su cercanía geográfica a la ciudad de Wuhan, esta región afrontó la pandemia con éxito, ya que contaba con la experiencia previa de la epidemia del SARS en el 2003, y también porque la población tiene una mayor conciencia ciudadana que las de otros países. Las acciones que han convertido a Taiwán en un ejemplo de cómo puede desarrollarse una política de salud pública eficiente para controlar la diseminación del SARS-CoV-2 son las siguientes: la utilización de recursos electrónicos e informáticos, el empleo correcto de la información, el desarrollo de pruebas de laboratorio propias y, por último, el manejo cuidadoso y efectivo de los casos sospechosos, los contactos y los pacientes hospitalizados. Esta experiencia es un ejemplo importante para nuestro país.
The management of the SARS-CoV-2 infection in Taiwan has been listed as one of the most efficient in the world. Its population size is almost equivalent to that of Peru, but the rate of infections has been less than 600 and the mortality rate has been extremely low: only seven patients died until December. Despite its geographical proximity to the city of Wuhan, Taiwan successfully faced the pandemic because of its previous experience with the SARS epidemic in 2003 and its greater public awareness compared to that in other countries. The actions that have made of Taiwan an example of how to develop an efficient public health policy to control the spread of SARS-CoV-2 are the following: the use of electronic and computer resources; the appropriate use of information; the development of its own laboratory tests; and, finally, the careful and effective management of suspected cases, contacts and hospitalized patients. This experience is an important example for our country.
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Tall- and dwarf-sized elephant grass cultivars have been developed for cut-and-carry system. Dwarf clones have better digestibility; on the other hand, tall-sized cultivars are more productive. The aim was to verify which grass would be most recommended for cut-and-carry: tall-sized (Elephant B and IRI-381) or dwarf (Taiwan A-146 2.37 and Mott) elephant grass cultivars to feed 24 male sheep, aged between 4 and 5 months, uncastrated, weighing approximately 24.08 ± 1.76 kg body weight which were sampled on intake, digestibility, performance, ingestive behavior, nitrogen balance, microbial protein synthesis, metabolic parameters, and ruminal degradability. This research was divided into two experiments: experiment 1 lasted 38 days, seven for adaptation and 31 for data collection. Elephant grass cultivars were supplied with a mineral mixture. Data collected were intake, digestibility, ingestive behavior, metabolic parameters, microbial protein synthesis, and performance submitted to a completely randomized design. For experiment 2, three rumen fistulae animals were sampled, lasting 20 days. In this case, a randomized block in split-plot design was applied. Both designs were with P < 0.05 and analyzed through SAS statistical software. Mott and Taiwan A-146 2.37 cultivars provided greater intake, digestibility, weight gain, feeding time, nitrogen retention, production and efficiency of microbial protein synthesis, dry matter (DM) and neutral detergent fiber (NDF) degradability, and DM, crude protein, and NDF, but shorter rumination time rather than Elephant B and IRI-381. There was also a significant difference for glucose, triglycerides, plasma urea, total serum protein, urinary urea (mg/L), and urea excretion in urine (mg/day). Dwarf elephant grass cultivars as Mott and Taiwan A-146 2.37 have greater nutritional value than tall-sized Elephant B and IRI-381. Dwarf elephant grass is recommended for cut-and-carry system.
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Dieta/veterinária , Digestão , Ingestão de Alimentos , Pennisetum/crescimento & desenvolvimento , Rúmen/fisiologia , Carneiro Doméstico/fisiologia , Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal , Animais , Pennisetum/químicaRESUMO
Leishmaniasis is prevalent in Southern Europe, the Middle East, India, Africa, and Central and South America. Cutaneous leishmaniasis may spontaneously heal over time without treatment; however, risk of visceral dissemination and the impact of cosmetic defect are important concerns. We report a Case of cutaneous leishmaniasis in a patient who ever traveled to Mexico before the onset of a deteriorating wound around the swollen left eyebrow. A diagnosis of infection with Leishmania mexicana was made based on histopathological examination and molecular identification. Systemic treatment with liposomal amphotericin B and ketoconazole were administered with gradual healing of the lesion. Also, this traveler case implicates that the spread of endemic parasitic diseases may be a concealed risk on the public health for Taiwan underlying globalization.
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Leishmaniose Cutânea/diagnóstico , Leishmaniose Cutânea/tratamento farmacológico , Doença Relacionada a Viagens , Adulto , Anfotericina B/uso terapêutico , DNA de Protozoário/genética , Humanos , Cetoconazol/uso terapêutico , Leishmania mexicana/genética , Leishmania mexicana/isolamento & purificação , Leishmaniose Cutânea/patologia , Masculino , Resultado do TratamentoRESUMO
BACKGROUND: Koelreuteria henryi Dummer is an indigenous plant in Taiwan. The species has been used in traditional folk medicine for the promotion of liver functions and for treating malaria and urethritis. The present study investigated the antioxidant activity of the flower extract of Koelreuteria henryi Dummer. The extraction conditions were optimized by the contents of total phenolic acids and total flavonoids, and antioxidant activity assays. Moreover, an in vitro study for investigating antioxidant activity of K. henryi flower extract was demonstrated by hydrogen peroxide (H2O2)-induced apoptosis. RESULTS: K. henryi flower extracted for 150 min showed high contents of total phenolic acids and total flavonoids. In an in vitro model, L929 cells were pretreated with K. henryi flower extract, and then treated with H2O2 to induce oxidative damage. Results demonstrated that H2O2-induced apoptosis was inhibited by the treatment of 200 µg/ml K. henryi flower extract through the mitochondria-mediated pathway and mitogen-activated protein kinase (MAPK) pathway. The caspase 8/9 activity and expression of p-p38 and pERK were repressed by K. henryi flower extract. In addition, the prevention of H2O2-induced apoptosis by K. henryi flower extract activated the nuclear factor-erythroid 2-related factor (Nrf2) stress response pathway to transcript heme oxygenase 1 (HO-1). Also, K. henryi flower extract prevented H2O2-induced apoptosis through HO-1 production, as evident by the use of HO-1 inhibitor. CONCLUSIONS: The present study demonstrated that K. henryi flower extract could inhibit the H2O2-induced apoptosis in L929 cells through the activation of the Nrf2/HO-1 pathway.
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Extratos Vegetais/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Sapindaceae/química , Antioxidantes/farmacologia , Flavonoides/análise , Western Blotting , Apoptose , Flores/química , Heme Oxigenase-1 , Fator 2 Relacionado a NF-E2 , Caspase 8 , Peróxido de HidrogênioRESUMO
Anagyrus callidus Triapitsyn, Andreason Perring (Hymenoptera: Encyrtidae), recently described from southern California, USA and Mexico, is a primary parasitoid of the pink hibiscus mealybug, Maconellicoccus hirsutus (Green) (Hemiptera: Pseudococcidae). This wasp species previously was misidentified as Anagyrus kamali Moursi, which was introduced and released as such in the United States (California and Florida) and Mexico. In this paper, the origin of A. callidus is shown to be from Taiwan, based on differences in the morphology and molecular sequences of voucher specimens of an earlier colony of the misidentified A. kamali from Puerto Rico (released in August 2002 in southern Florida), and specimens that originated in southern Taiwan.
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Hemípteros , Himenópteros , Animais , California , Florida , Hibiscus , México , Porto Rico , TaiwanRESUMO
We determined the prevalence of infection and genetic identity of Hepatozoon spp. harbored by Rhipicephalus sanguineus sensu lato ticks in Taiwan. A total of 1082 ticks were collected from dogs and DNA extraction was performed from individual tick specimens. Hepatozoon infection was detected by performing a nested-PCR assay based on the 18S small subunit ribosomal RNA (ssrRNA) gene. The genetic identity of detected Hepatozoon was identified by gene sequencing and phylogenetic analysis. Hepatozoon infection was detected in nymphs, males and females of R. sanguineus s. l. ticks with an infection rate of 20.8%, 22.8% and 29.4%, respectively. Sequence and phylogenetic analysis revealed that these Hepatozoon spp. of Taiwan were genetically affiliated to the same clade within the genospecies of H. canis and can be discriminated from other genospecies of H. americanum and H. felis. Intraspecies analysis based on the genetic distance (GD) values indicates a lower level (GD < 0.005) genetic divergence within the same genospecies of H. canis detected in Taiwan, Brazil and Spain. Interspecies analysis also reveals a higher heterogeneity of Taiwan strains distinguished from other genospecies of H. felis (GD > 0.040) and H. americanum (GD > 0.056). This study provides the first molecular evidence of H. canis detected and identified in various stages of R. sanguineus s. l. ticks in Taiwan. Detection of H. canis in unfed male ticks may imply the possible mechanism of transstadial survival in R. sanguineus s. l. ticks. Further investigations on Hepatozoon spp. harbored by various vector ticks in Taiwan may illustrate the epidemiological significance of this parasite.
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Coccidiose/veterinária , Doenças do Cão/epidemiologia , Doenças do Cão/parasitologia , Cães/parasitologia , Eucoccidiida/genética , Rhipicephalus sanguineus/parasitologia , Animais , Vetores Aracnídeos/parasitologia , Brasil/epidemiologia , Coccidiose/epidemiologia , DNA de Protozoário/genética , Eucoccidiida/isolamento & purificação , Feminino , Masculino , Ninfa/parasitologia , Filogenia , Reação em Cadeia da Polimerase , Prevalência , RNA Ribossômico 18S/genética , Análise de Sequência de DNA , Espanha/epidemiologia , Taiwan/epidemiologiaRESUMO
Abstract Background To better understand the trends of behavioral and psychological symptoms of dementia (BPSD) over the disease progression is important to provide psychoeducation for dementia caregivers. Objective This study examined the severity and occurrence of BPSD across the various degrees of the disease. Methods This study was a cross-sectional design. Patients (N = 276) who had dementia from July 2001 to October 2008 were surveyed and assessed for dementia stage, using the clinical dementia rating scale (CDR). BPSD was evaluated using the Neuropsychiatric Inventory (NPI). We examined the differences between the severities and occurrence of the individual's BPSD among various CDR stages with the Kruskal-Wallis test and Chi-square test. Results Delusion (p = 0.01), agitation/aggression (p = 0.033), apathy/indifference (p = 0.009), aberrant motor behavior (p < 0.001), nighttime behavior disturbances (p < 0.001), and eating abnormalities (p = 0.001) were significantly different among stages of dementia. The severity of BPSD became exacerbated over the course of the disease, and was highest in moderate (CDR = 2) or severe (CDR = 3) dementia. The occurrence of BPSD was highest when the CDR equaled 2 (97.5%). Discussion The association of global (or certain) BPSD, across different stages of dementia, is a non-linear relationship. These findings suggest the importance of taking into account clinical dementia stage for managing BPSD.
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A new species of the thorid shrimp genus Lebbeus White, 1847 is reported upon from a deep-sea cold seep site off southwestern Taiwan. The new species belongs to the group characterized by the possession of epipod only on maxilliped III and pereiopod I, and appears closest to L. curvirostris Zarenkov, 1976, known only from off Peru, Eastern Pacific and L. manus Komai & Collins, 2009 from the Manus Basin, Bismarck Sea, Southwest Pacific. It differs from the latter two species in having a larger supraorbital tooth and more numerous spines on the meri of the pereiopods III to V. The present new species is the fifth of the genus known from waters around Taiwan.
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Decápodes , Animais , Peru , TaiwanRESUMO
In the last few decades, many forests have been cut down to make room for cultivation and to increase food or energy crops production in developing countries. In this study, carbon sequestration and wood production were evaluated on afforested farms by integrating the Gaussian diameter distribution model and exponential diameter-height model derived from sample plots of an afforested hardwood forest in Taiwan. The quantity of sequestrated carbon was determined based on aboveground biomass. Through pilot tests run on an age-volume model, an estimation bias was obtained and used to correct predicted volume estimates for a farm forest over a 20-year period. An estimated carbon sequestration of 11,254 t C was observed for a 189ha-hardwood forest which is equivalent to 41,264 t CO2. If this amount of carbon dioxide were exchanged on the Chicago Climate Exchange (CCX) market, the income earned would be 821 US$ ha - 1. Carbon sequestration from rice (Oryza sativa) or sugarcane (Saccharum officinarum) production is discharged as a result of straw decomposition in the soil which also improves soil quality. Sugarcane production does not contribute significantly to carbon sequestration, because almost all the cane fiber is used as fuel for sugar mills. As a result of changing the farming systems to hardwood forest in this study area, carbon sequestration and carbon storage have increased at the rate of 2.98 t C ha - 1 year - 1. Net present value of afforestation for a 20-year period of carbon or wood management is estimated at around US$ 30,000 given an annual base interest rate of 3 %.(AU)
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Sequestro de Carbono , 24444 , Conservação dos Recursos Naturais , Biomassa , Solo/análiseRESUMO
In the last few decades, many forests have been cut down to make room for cultivation and to increase food or energy crops production in developing countries. In this study, carbon sequestration and wood production were evaluated on afforested farms by integrating the Gaussian diameter distribution model and exponential diameter-height model derived from sample plots of an afforested hardwood forest in Taiwan. The quantity of sequestrated carbon was determined based on aboveground biomass. Through pilot tests run on an age-volume model, an estimation bias was obtained and used to correct predicted volume estimates for a farm forest over a 20-year period. An estimated carbon sequestration of 11,254 t C was observed for a 189ha-hardwood forest which is equivalent to 41,264 t CO2. If this amount of carbon dioxide were exchanged on the Chicago Climate Exchange (CCX) market, the income earned would be 821 US$ ha - 1. Carbon sequestration from rice (Oryza sativa) or sugarcane (Saccharum officinarum) production is discharged as a result of straw decomposition in the soil which also improves soil quality. Sugarcane production does not contribute significantly to carbon sequestration, because almost all the cane fiber is used as fuel for sugar mills. As a result of changing the farming systems to hardwood forest in this study area, carbon sequestration and carbon storage have increased at the rate of 2.98 t C ha - 1 year - 1. Net present value of afforestation for a 20-year period of carbon or wood management is estimated at around US$ 30,000 given an annual base interest rate of 3 %.
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Conservação dos Recursos Naturais , 24444 , Sequestro de Carbono , Biomassa , Solo/análiseRESUMO
The effect of duckweed (DW) supplementation was evaluated on dry matter intake (DMI), presence and duration of estrus, percentage of ewes repeating estrus and pregnancy rate, as well as the concentration of progesterone (P4) in multiparous crossbred ewes from Pelibuey, Dorper, and Katahdin breeds, fed with Taiwan grass hay (TWH). Eighteen ewes with 39.7±4 kg mean body weight, kept in individual pens, were randomly assigned to one of the following treatments: T1: TWH, T2: TWH plus 200 g DW, T3: TWH plus 300 g DW. The ewes were synchronized with 40 mg fluorogestone acetate (FGA) and 400 UI equine chorionic gonadotropin (eCG). Data were analyzed as a completely randomized design using the GLM procedure. DW supplementation had no effect on dry matter intake (p>0.05); however, a slight decrease of TWH intake was observed as DW supplementation increased. No differences (p>0.05) were found in the beginning of estrus, percentage of ewes presenting it, its duration, or pregnancy rate. There were no differences (p>0.05) on P4 concentration among treatments, or treatmentxperiod interaction (p>0.05). However the period was significant (p<0.01), since the P4 levels increased as time increased after the removal of the FGA device and eCG application.
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There are very few microbiological data on wound infections following snakebites. The objective of this study was to investigate the treatment of secondary infection following snakebites in central Taiwan. Microbiological data and antibiotic sensitivity of wound cultures were retrospectively analyzed from December 2005 to October 2007 in a medical center in central Taiwan. A total of 121 snakebite patients participated in the study. Forty-nine (40.5%) subjects were bitten by cobra (Naja atra); 34 of them had secondary infection, and 24 of them (70.6%) needed surgical intervention. Cobra bites caused more severe bacterial infection than other snakebites. Morganella morganii was the most common pathogen, followed by Aeromonas hydrophila and Enterococcus. Gram-negative bacteria were susceptible to amikacin, trimethoprim/sulfamethoxazole, cefotaxime, cefepime, ciprofloxacin, and piperacillin/tazobactam. Enterococcus were susceptible to ampicillin, gentamicin, penicillin and vancomycin. It is reasonable to choose piperacillin/tazobactam, quinolone, second- or third-generation cephalosporin for empirical therapy following snakebite. Surgical intervention should be considered for invasive soft tissue infections.(AU)
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Humanos , Mordeduras de Serpentes , Infecções Bacterianas , Infecção dos Ferimentos , Ferimentos e Lesões , AntibacterianosRESUMO
There are very few microbiological data on wound infections following snakebites. The objective of this study was to investigate the treatment of secondary infection following snakebites in central Taiwan. Microbiological data and antibiotic sensitivity of wound cultures were retrospectively analyzed from December 2005 to October 2007 in a medical center in central Taiwan. A total of 121 snakebite patients participated in the study. Forty-nine (40.5%) subjects were bitten by cobra (Naja atra); 34 of them had secondary infection, and 24 of them (70.6%) needed surgical intervention. Cobra bites caused more severe bacterial infection than other snakebites. Morganella morganii was the most common pathogen, followed by Aeromonas hydrophila and Enterococcus. Gram-negative bacteria were susceptible to amikacin, trimethoprim/sulfamethoxazole, cefotaxime, cefepime, ciprofloxacin, and piperacillin/tazobactam. Enterococcus were susceptible to ampicillin, gentamicin, penicillin and vancomycin. It is reasonable to choose piperacillin/tazobactam, quinolone, second- or third-generation cephalosporin for empirical therapy following snakebite. Surgical intervention should be considered for invasive soft tissue infections.(AU)
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Humanos , Animais , Mordeduras de Serpentes/imunologia , Mordeduras de Serpentes/microbiologia , Infecção dos Ferimentos/patologia , Infecção dos Ferimentos/terapiaRESUMO
The objective of this study was to isolate, characterize, and identify lactic acid bacteria (LAB) from ripe mulberries collected in Taiwan. Ripe mulberry samples were collected at five mulberry farms, located in different counties of Taiwan. Eighty-eight acid-producing cultures were isolated from these samples, and isolates were divided into classes first by phenotype, then into groups by restriction fragment length polymorphism (RFLP) analysis and sequencing of 16S ribosomal DNA (rDNA). Phenotypic and biochemical characteristics led to identification of four bacterial groups (A to D). Weissella cibaria was the most abundant type of LAB distributed in four mulberry farms, and Lactobacillus plantarum was the most abundant LAB found in the remaining farm. Ten W. cibaria and one Lactococcus lactis subsp. lactis isolate produced bacteriocins against the indicator strain Lactobacillus sakei JCM 1157T. These results suggest that various LAB are distributed in ripe mulberries and W. cibaria was the most abundant LAB found in this study.
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The objective of this study was to isolate, characterize, and identify lactic acid bacteria (LAB) from ripe mulberries collected in Taiwan. Ripe mulberry samples were collected at five mulberry farms, located in different counties of Taiwan. Eighty-eight acid-producing cultures were isolated from these samples, and isolates were divided into classes first by phenotype, then into groups by restriction fragment length polymorphism (RFLP) analysis and sequencing of 16S ribosomal DNA (rDNA). Phenotypic and biochemical characteristics led to identification of four bacterial groups (A to D). Weissella cibaria was the most abundant type of LAB distributed in four mulberry farms, and Lactobacillus plantarum was the most abundant LAB found in the remaining farm. Ten W. cibaria and one Lactococcus lactis subsp. lactis isolate produced bacteriocins against the indicator strain Lactobacillus sakei JCM 1157(T). These results suggest that various LAB are distributed in ripe mulberries and W. cibaria was the most abundant LAB found in this study.
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The objective of this study was to isolate, characterize, and identify lactic acid bacteria (LAB) from ripe mulberries collected in Taiwan. Ripe mulberry samples were collected at five mulberry farms, located in different counties of Taiwan. Eighty-eight acid-producing cultures were isolated from these samples, and isolates were divided into classes first by phenotype, then into groups by restriction fragment length polymorphism (RFLP) analysis and sequencing of 16S ribosomal DNA (rDNA). Phenotypic and biochemical characteristics led to identification of four bacterial groups (A to D). Weissella cibaria was the most abundant type of LAB distributed in four mulberry farms, and Lactobacillus plantarum was the most abundant LAB found in the remaining farm. Ten W. cibaria and one Lactococcus lactis subsp. lactis isolate produced bacteriocins against the indicator strain Lactobacillus sakei JCM 1157T. These results suggest that various LAB are distributed in ripe mulberries and W. cibaria was the most abundant LAB found in this study.
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PIP: This article explains that birth delays skew developing world's fertility figures. When successive groups of women who have delayed childbearing start having children, the rapid fertility decline stalls. Such change in the timing of childbearing skews the total fertility rate (TFR). Analysis of the tempo component of TFR trends in Taiwan suggests that tempo effects reduced its TFR by about 10% in the late 1970s and early 1990s and by about 19% in the late 1980s. In Colombia, on the basis of increasing mean maternal age at childbirth between the 1970s and the late 1980s, tempo distortions of the TFR during the most of the 1980s seem likely. Moreover, many developing countries are now experiencing rapid fertility declines that are in part attributable to tempo changes. These changes have accelerated past fertility transitions, but they also make these countries vulnerable to future stalls in fertility when the delays in childbearing end. Since fertility reductions caused by tempo effects lead to real declines in birth rates and hence in population growth, countries that wish to reduce birth rates can take actions that encourage women to delay marriage and the onset of childbearing.^ieng
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Coeficiente de Natalidade , Fertilidade , Dinâmica Populacional , Pesquisa , América , Ásia , China , Colômbia , Demografia , Países em Desenvolvimento , Ásia Oriental , América Latina , População , América do Sul , TaiwanRESUMO
This reassessment is limited to observations concerning trends in mortality and fertility and concerning longrun prospects for population growth. Recorded changes in mortality are compared with 3 projections made many years ago. Projections of European mortality made in 1941-42 understated by a wide margin the actual increase in expectation of life because of unforeseen technological changes in the prevention and cure of fatal disease. On the other hand, a projection made in 1955 for India, foreseeing a rapid rise in the 1950s and slower progress later on because of the exhaustion of the easier gains, appears to have been accurate and also to depict the prospects in other populations of relatively high mortality and low income. A different projection of life expectancy in Mexico was also quite close to actual changes in Mexican mortality; it was based on a universal curve constructed to represent how life expectancy rises, increasing ever more slowly as it approaches an upper limit. This curve (1 for each sex), constructed for projection of Mexican mortality, is employed as a standard of comparison for mortality changes in many countries. A number have followed the standard for females very closely for more than 3 decades; in developed countries, male life expectancy has generally fallen short of the standard. The almost universal low fertility in developed countries contrasts with the great diversity of levels and trends of fertility in developing countries, some of which retain undiminished high fertility and others of which have recently attained rates of childbearing as low as in the developed areas. Instances of surprisingly little change and surprisingly rapid change in fertility are described. In the future, growth of populations of developed countries will probably be slight; the future rate of increase in the developing areas depends on the unpredictable timing and pace of childbearing reduction in populations where fertility remains high. In the long run, world population growth may resume its typical pattern of moderate growth interrupted by catastrophic setbacks.