Your browser doesn't support javascript.
loading
: 20 | 50 | 100
1 - 20 de 71
1.
Physiother Res Int ; 29(2): e2086, 2024 Apr.
Article En | MEDLINE | ID: mdl-38572991

BACKGROUND AND OBJECTIVE: Reduced functional capacity, dyspnea, fatigue, and changes in body composition are common in patients with post-COVID-19 syndrome (PCS), and cardiopulmonary rehabilitation may improve these parameters. Thus, the present study verified the effects of cardiopulmonary rehabilitation (respiratory, aerobic, and resistance muscle training) on submaximal exercise tolerance, dyspnea, fatigue, and body composition. METHODS: This controlled and randomized clinical trial applied a six-week outpatient intervention protocol in individuals over 18 years old (n = 33) with a diagnosis of COVID-19 confirmed by polymerase chain reaction. These individuals were allocated to cardiopulmonary rehabilitation (n = 17) or control groups (i.e., educational lectures; n = 16). The cardiopulmonary rehabilitation group performed respiratory, aerobic, and resistance muscle training. Submaximal exercise tolerance, dyspnea, fatigue, and body composition were assessed before and after the protocol. RESULTS: After 6 weeks, the cardiopulmonary rehabilitation group increased the tolerance to submaximal exercise, with a difference of 100.46 m (95% confidence interval [CI]: 7.40-193 m) in the distance walked on the six-minute walk test, reduced dyspnea (-1.45, 95% CI: -1.98--0.92) in the modified Medical Research Council, and increased 0.63 kg (95% CI: 0.09-1.18 kg) of muscle mass in the upper limbs compared with the control group. CONCLUSION: The six-week cardiopulmonary rehabilitation protocol improved functional capacity, reduced dyspnea, and increased muscle mass in the upper limbs in individuals with PCS. Thus, these results supported the protocol use in this population and encourage further studies to assess its effectiveness in a large sample.


COVID-19 , Post-Acute COVID-19 Syndrome , Humans , Body Composition , Dyspnea , Exercise Tolerance/physiology , Fatigue , Quality of Life , Adult
2.
Anim Reprod ; 21(1): e20230123, 2024.
Article En | MEDLINE | ID: mdl-38510564

The impact of GnRH treatment on the day of TAI in beef cows has received limited investigation, especially concerning its association with estrus expression. Consequently, two experiments were conducted to assess the potential of GnRH treatment on the day of TAI to enhance fertility according to the expression or not of estrus in beef cows. Experiment 1 aimed to determine ovulation rate and luteal function, while Experiment 2 aimed to determine the effect of the two GnRH treatment approaches on pregnancy rate. In Experiment 1, multiparous Brangus suckling cows (n = 17) were submitted to an 8-day TAI protocol. Estrus occurrence was evaluated based on chalk removal on D10 (TAI) and cows were assigned to receive GnRH (25µg lecirelin; im) according to the group: GnRH (n = 7), regardless of estrus expression; or selectGnRH (n = 10), only cows not detected in estrus. Ovulation rate occurring until 77h after IVD removal did not differ (p = 0.17) between GnRH (85.7%; 6/7) and selectGnRH (100%; 10/10). Also, corpus luteum size and serum progesterone concentration were not affected (p>0.05) by treatments. In Experiment 2, crossbred taurine suckled cows (n = 384) were submitted to the same protocol as described in Experiment 1 and were randomly allocated to GnRH or selectGnRH groups. There was no difference in P/AI between groups (selectGnRH = 55.6%; GnRH = 54.3%; p = 0.7) 30 days after TAI. As expected, there was a pronounced effect (p<0.0001) of estrus expression on P/AI (Estrus = 61.5%; No estrus = 33.0%), regardless of group. In summary, ovulation timing and rate and luteal function did not differ between groups. Also, GnRH administration only in cows that do not show estrus is recommended, considering hormone savings and similar conception rate.

3.
Sci Rep ; 14(1): 3236, 2024 02 08.
Article En | MEDLINE | ID: mdl-38332227

Machado-Joseph disease (MJD) is a neurodegenerative disorder characterized by widespread neuronal death affecting the cerebellum. Cell therapy can trigger neuronal replacement and neuroprotection through bystander effects providing a therapeutic option for neurodegenerative diseases. Here, human control (CNT) and MJD iPSC-derived neuroepithelial stem cells (NESC) were established and tested for their therapeutic potential. Cells' neuroectodermal phenotype was demonstrated. Brain organoids obtained from the Control NESC showed higher mRNA levels of genes related to stem cells' bystander effects, such as BDNF, NEUROD1, and NOTCH1, as compared with organoids produced from MJD NESC, suggesting that Control NESC have a higher therapeutic potential. Graft-derived glia and neurons, such as cells positive for markers of cerebellar neurons, were detected six months after NESC transplantation in mice cerebella. The graft-derived neurons established excitatory and inhibitory synapses in the host cerebella, although CNT neurons exhibited higher excitatory synapse numbers compared with MJD neurons. Cell grafts, mainly CNT NESC, sustained the bystander effects through modulation of inflammatory interleukins (IL1B and IL10), neurotrophic factors (NGF), and neurogenesis-related proteins (Msi1 and NeuroD1), for six months in the mice cerebella. Altogether this study demonstrates the long-lasting therapeutic potential of human iPSC-derived NESC in the cerebellum.


Induced Pluripotent Stem Cells , Machado-Joseph Disease , Mice , Animals , Humans , Induced Pluripotent Stem Cells/metabolism , Bystander Effect , Neurons/metabolism , Cerebellum/metabolism , Machado-Joseph Disease/metabolism
4.
Neurourol Urodyn ; 43(3): 672-679, 2024 Mar.
Article En | MEDLINE | ID: mdl-38247352

AIMS: To investigate the frequency and the factors associated with urinary incontinence (UI) in a sample of middle-aged and older women with lower limb osteoarthritis (OA). METHODS: Women aged 50 years or older with clinical hip/knee OA diagnoses were recruited for this cross-sectional study. Self-reported UI and type, sociodemographic characteristics, medical conditions, physical activity level, anthropometric and body composition measurements, muscle strength, and physical function were assessed. Uni and multivariable logistic regression were used to investigate the factors associated with UI. RESULTS: Among 100 middle-aged and older women (mean 67.27 ± 8.77 SD years), 67% reported UI. In the UI group, 33% reported stress UI, 36% reported urgency UI, and 31% reported mixed UI. In the univariate analysis, age, level of physical activity, pulmonary disease, number of medications, body mass index (BMI), number of deliveries, and activity limitation were significantly associated with UI. In the multivariable analysis, older age (60-69 years OR: 4.91, 95% CI: 1.25-19.36; ≥70 years OR: 8.06, 95% CI: 1.96-33.22), compared to 50-59 years, morbid obesity (OR: 14.10, 95% CI: 1.36-146.48), compared to BMI < 30 kg/m2 , and activity limitation (OR: 5.31, 95% CI: 1.61-17.54), assessed as short physical performance battery ≤8, remained significantly associated with UI. CONCLUSIONS: UI was highly frequent among middle-aged and older women with hip/knee OA. Older age, activity limitation, and morbid obesity were independently associated with UI. Interventions targeting physical function and weight management must be considered to prevent and treat UI in this population.


Obesity, Morbid , Osteoarthritis, Hip , Osteoarthritis, Knee , Urinary Incontinence, Stress , Urinary Incontinence , Middle Aged , Humans , Female , Aged , Osteoarthritis, Knee/complications , Osteoarthritis, Knee/epidemiology , Cross-Sectional Studies , Osteoarthritis, Hip/complications , Osteoarthritis, Hip/epidemiology , Obesity, Morbid/complications , Outpatients , Urinary Incontinence/epidemiology , Urinary Incontinence/etiology , Risk Factors , Urinary Incontinence, Stress/complications , Prevalence
5.
Geriatr Nurs ; 55: 333-338, 2024.
Article En | MEDLINE | ID: mdl-38154414

Knee instability in patients with knee osteoarthritis (KOA) is associated with fear of falling (FoF). This study aimed to investigate the prevalence and the factors associated with FoF in older women with KOA. A cross-sectional study was conducted with 93 older women with KOA. Sociodemographic variables, medical conditions, handgrip strength, and anthropometric and body composition measurements were assessed. The Short Physical Performance Battery was used to measure functional performance. The Western Ontario and McMaster Universities Osteoarthritis Index was applied to assess pain, stiffness, and disability. FoF was assessed by the Falls Efficacy Scale-International. The prevalence of FoF was high (88.2 %). Disability, history of falls, handgrip strength, obesity, number of medications, and pain were independently associated with FoF. Our findings suggest that health professionals should investigate FoF when evaluating older women with KOA and address these risk factors when developing strategies to prevent or minimize FoF in this population.


Osteoarthritis, Knee , Humans , Female , Aged , Cross-Sectional Studies , Hand Strength , Fear , Pain , Independent Living
6.
Curr Nutr Rep ; 12(4): 567-580, 2023 Dec.
Article En | MEDLINE | ID: mdl-37642932

PURPOSE OF REVIEW: Fucoxanthin is an orange-red xanthophyll carotenoid found in brown seaweeds and known for its many bioactive properties. In recent years, the bioactive properties of fucoxanthin have been widely explored, making it a compound of immense interest for various health applications like anti-cancer, anti-tumour, anti-diabetic and anti-obesity properties. However, the poor bioavailability and instability of fucoxanthin in the gastrointestinal tract have major limitations. Encapsulation is a promising approach to overcome these challenges by enclosing fucoxanthin in a protective layer, such as liposomes or nano-particles. Encapsulation can improve the stability of fucoxanthin by protecting it from exposure to heat, pH, illumination, gastric acids and enzymes that can accelerate its degradation. RECENT FINDINGS: Studies have shown that lipid-based encapsulation systems such as liposomes or nano-structured lipid carriers may solubilise fucoxanthin and enhance its bioavailability (from 25 to 61.2%). In addition, encapsulation can also improve the solubility of hydrophobic fucoxanthin, which is important for its absorption and bioavailability. This review highlights the challenges involved in the absorption of fucoxanthin in the living system, role of micro- and nano-encapsulation of fucoxanthin and their potential to enhance intestinal absorption.


Food Ingredients , Liposomes , Humans , Biological Availability , Xanthophylls/chemistry , Lipids
8.
Front Genet ; 14: 1114742, 2023.
Article En | MEDLINE | ID: mdl-37025454

The CYP2C19 gene, located in the CYP2C cluster, encodes the major drug metabolism enzyme CYP2C19. This gene is highly polymorphic and no-function (CYP2C19*2 and CYP2C19*3), reduced function (CYP2C19*9) and increased function (CYP2C19*17) star alleles (haplotypes) are commonly used to predict CYP2C19 metabolic phenotypes. CYP2C19*17 and the genotype-predicted rapid (RM) and ultrarapid (UM) CYP2C19 metabolic phenotypes are absent or rare in several Native American populations. However, discordance between genotype-predicted and pharmacokinetically determined CYP2C19 phenotypes in Native American cohorts have been reported. Recently, a haplotype defined by rs2860840T and rs11188059G alleles in the CYP2C cluster has been shown to encode increased rate of metabolism of the CYP2C19 substrate escitalopram, to a similar extent as CYP2C19*17. We investigated the distribution of the CYP2C:TG haplotype and explored its potential impact on CYP2C19 metabolic activity in Native American populations. The study cohorts included individuals from the One Thousand Genomes Project AMR superpopulation (1 KG_AMR), the Human Genome Diversity Project (HGDP), and from indigenous populations living in Brazil (Kaingang and Guarani). The frequency range of the CYP2C:TG haplotype in the study cohorts, 0.469 to 0.598, is considerably higher than in all 1 KG superpopulations (range: 0.014-to 0.340). We suggest that the high frequency of the CYP2C:TG haplotype might contribute to the reported discordance between CYP2C19-predicted and pharmacokinetically verified CYP2C19 metabolic phenotypes in Native American cohorts. However, functional studies involving genotypic correlations with pharmacokinetic parameters are warranted to ascertain the importance of the CYP2C:TG haplotype.

10.
Enferm. foco (Brasília) ; 14: 1-7, mar. 20, 2023. tab
Article Pt | LILACS, BDENF | ID: biblio-1525355

Objetivo: Relatar o conhecimento e a percepção dos profissionais enfermeiros e médicos sobre a moralidade do aborto induzido e sua legislação. Métodos: Estudo quantitativo, envolvendo 39 Enfermeiros e Médicos de duas Maternidades do sul do Brasil. Para a coleta de dados foi utilizado o "Mosaico de Opiniões Sobre o Aborto Induzido" e um questionário complementar. Para análise descritiva e associações foi utilizado o pacote estatístico Data Analysis and Statistical Software. Resultados: Constatou-se que os profissionais possuem adequado conhecimento a respeito da legislação, conhecimento insuficiente a respeito dos documentos necessários para o aborto legal e sobre o direito a objeção de consciência, sendo este último principalmente entre os enfermeiros. Os profissionais defendem outras possibilidades de aborto na legislação, e a respeito do Mosaico, predominam os padrões liberais em comparação aos conservadores. Conclusão: Se faz necessária a discussão sobre o tema, ampliando o conhecimento a respeito dos direitos sexuais e reprodutivos das mulheres e sobre a conduta durante a assistência ao aborto. (AU)


Objective: Report the knowledge and perception of nurses and physicians about the morality of induced abortion and its legislation. Methods: Quantitative study, involving 39 nurses and physicians at two maternity hospitals in southern Brazil. For data collection the "Mosaic of Opinions on Induced Abortion" and a complementary questionnaire were used. For descriptive analysis and associations, the Data Analysis and Statistical Software statistical package was used. Results: It was found that the professionals have adequate knowledge about the legislation, insufficient knowledge about the documents necessary for legal abortion and about the right to conscientious objection, the latter occurred mainly among nurses. Professionals defend other possibilities of abortion in the legislation, and regarding the Mosaic, liberal standards prevail in comparison to conservatives. Conclusion: It is necessary to discuss the topic, expanding knowledge about women's sexual and reproductive rights and about conduct during abortion care. (AU)


Objetivo: Informar el conocimiento y percepción de enfermeras y médicos profesionales sobre la moralidad del aborto inducido y su legislación. Métodos: Estudio cuantitativo, que involucró a 39 enfermeras y médicos de dos maternidades del sur de Brasil. Para la recolección de datos se utilizó el "Mosaico de Opiniones sobre el Aborto Inducido" y un cuestionario complementario. Para el análisis descriptivo y las asociaciones se utilizó el paquete estadístico Data Analysis and Statistical Software. Resultados: Se constató que los profesionales tienen conocimiento adecuado sobre la legislación, conocimiento insuficiente sobre los documentos necesarios para el aborto legal y sobre el derecho a la objeción de conciencia, siendo este último principalmente entre enfermeras. Los profesionales defienden otras posibilidades de aborto en la legislación, y con respecto a Mosaic, los estándares liberales prevalecen en comparación con los conservadores. Conclusión: Es necesario discutir el tema, ampliando el conocimiento sobre los derechos sexuales y reproductivos de las mujeres y sobre la conducta durante la atención del aborto. (AU)


Abortion, Induced , Physicians , Health Knowledge, Attitudes, Practice , Knowledge , Nurses, Male
11.
Life (Basel) ; 13(2)2023 Jan 20.
Article En | MEDLINE | ID: mdl-36836655

Physical activity and diet are two predominant determinants of population health status that may influence each other. Physical activity has been identified as a behavior that may lead to a healthier diet and regulates eating behaviors. This research aimed to investigate how the level of physical activity is associated with the motivation related to eating behaviors and, consequently, the eating style individuals have on a daily basis. This was a cross-sectional study in which participants completed an online questionnaire that assessed the following variables: the level of physical activity, the motivation toward eating behavior, and the type of eating behavior. In total, 440 individuals (180 men and 260 women) who regularly exercised in gyms and fitness centers aged between 19 and 64 years (M = 33.84; SD = 10.09) took part in the study. The data were collected following the Declaration of Helsinki and with the approval of the Ethics Committee of the Polytechnic of Leiria. For the statistical analysis, mean and standard deviations were first calculated, as well as bivariate correlations between all the variables of interest. Then, structural equation model analyses were performed considering the levels of physical activity as the independent variable, motivations toward eating behavior as the mediators, and eating styles as the dependent variables. It was concluded that a greater level of physical activity leads to a more self-determined type of eating regulation, which in turn results in less constricted eating behaviors that are influenced by external factors and emotional factors.

13.
Registro; s.n; 2023. 116 p.
Thesis Pt | CONASS, SES-SP, SESSP-ISPROD, SES-SP, SESSP-ISACERVO | ID: biblio-1538345

Objetivo: Descrever a prevalência do aleitamento materno no município de Registro considerando a pandemia de COVID-19. Métodos: Trata-se de um estudo transversal de caráter descritivo com abordagem quantitativa, que incluiu uma amostra de 371 crianças, entre 0 a 24 meses, cadastradas em unidades de saúde da família do município de Registro-SP. Foi utilizado um questionário elaborado pelas pesquisadoras com o objetivo de coletar informações sobre o perfil da amamentação e o acesso ao serviço de saúde no pré-natal e pós-parto, tendo em vista as mudanças ocorridas na saúde com a pandemia de COVID-19. Em novembro e dezembro de 2022, foram entrevistadas as mães dos lactentes das 20 unidades de saúde do município. Os dados coletados foram digitados no Microsoft Excel, transportados para o Software Stata e analisados por meio dos indicadores propostos descrevendo as frequências absolutas (n) e relativas (%). O estudo foi aprovado pelo Comitê de Ética em Pesquisa do Instituto de Saúde sob o Parecer 5.636.209/2022. Resultados: Os resultados apontaram melhorias em relação à pesquisa realizada em 2011 no município, com taxas de aleitamento materno exclusivo até o sexto mês (54,1%) e aleitamento materno continuado até os 24 meses (58,2%) que superam a prevalência nacional. O aleitamento materno cruzado (9,2%), bem como o uso de chupetas (35,4%) e chuquinhas (46,3%) ficaram abaixo da média nacional. Conclusão: Embora tenha sido observado um cenário mais favorável em relação ao aleitamento materno no município em comparação a pesquisas anteriores e até mesmo em relação às médias nacionais, foram identificados desafios como a necessidade de incrementar a prática da amamentação na primeira hora de vida, a extensão do período de amamentação exclusiva e continuada, o correto registro das informações nas cadernetas de saúde das crianças e diminuir o uso de chupetas e mamadeiras. Verifica-se o quanto é imprescindível que ocorram abordagens abrangentes para aprimorar as práticas de amamentação e guiar políticas de saúde voltadas para mães e crianças, sobretudo em crises sanitárias.


Breast Feeding , COVID-19 , Primary Health Care
14.
São Paulo; Instituto de Saúde; 2023. 2 p. ilus.
Non-conventional Pt | CONASS, SES-SP, SESSP-ISPROD, SES-SP, SESSP-ISACERVO | ID: biblio-1552225

A dissertação aborda o panorama do aleitamento materno no município de Registro, Estado de São Paulo, considerando os impactos da pandemia de COVID-19 na saúde materno-infantil e nas práticas de atendimento correspondentes. O município testemunhou altas taxas de mortalidade infantil nos últimos anos.


Breast Feeding , COVID-19 , Primary Health Care
15.
Int Rev Psychiatry ; 34(3-4): 230-239, 2022.
Article En | MEDLINE | ID: mdl-36151833

Sexual minorities (individuals with a lesbian, gay, bisexual, queer, or other non-heterosexual identity) are at elevated risk of developing common mental health disorders relative to heterosexual people, yet have less favourable mental health service experiences and poorer treatment outcomes. We investigated the experiences of sexual minority service users accessing mental health services for common mental health problems (e.g. depression or anxiety) in the UK. We recruited 26 sexual minority adults with experiences of being referred to Improving Access to Psychological Therapies (IAPT) or primary care counselling services. Semi-structured interviews explored participants' experiences of service use and views on service development. Interviews were analysed using thematic analysis. Barriers to effective relationships with practitioners included service users' fears surrounding disclosure, and practitioners' lack of understanding and/or neglect of discussions around sexuality. Regarding service development, participants highlighted the value of seeing practitioners with shared identities and experiences, visible signs of inclusivity, sexual minority training, tailored supports, and technological adjuncts. Our findings offer insights into possible contributory factors to treatment inequalities, and highlight potential methods for improving service provision for sexual minorities.


Mental Health Services , Sexual and Gender Minorities , Adult , Female , Health Services Accessibility , Humans , Mental Health , Sexuality
16.
Sci Rep ; 12(1): 16203, 2022 09 28.
Article En | MEDLINE | ID: mdl-36171434

BRCA1 (Breast Cancer 1, early onset) is linked to breast and ovarian cancer predisposition. Still, the risks conferred by a significant portion of BRCA1 variants identified in the population remains unknown. Most of these variants of uncertain significance are missense alterations. However, the functional implications of small in-frame deletions and/or insertions (indels) are also difficult to predict. Our group has previously evaluated the functional impact of 347 missense variants using an extensively validated transcriptional activity assay. Here we show a systematic assessment of 30 naturally occurring in-frame indels located at the C-terminal region of BRCA1. We identified positions sensitive and tolerant to alterations, expanding the knowledge of structural determinants of BRCA1 function. We further designed and assessed the impact of four single codon deletions in the tBRCT linker region and six nonsense variants at the C-terminus end of BRCA1. Amino acid substitutions, deletions or insertions in the disordered region do not significantly impact activity and are not likely to constitute pathogenic alleles. On the other hand, a sizeable fraction of in-frame indels at the BRCT domain significantly impact function. We then use a Bayesian integrative statistical model to derive the probability of pathogenicity for each variant. Our data highlights the importance of assessing the impact of small in-frame indels in BRCA1 to improve risk assessment and clinical decisions for carriers.


Breast Neoplasms , Ovarian Neoplasms , Alleles , Amino Acid Substitution , BRCA1 Protein/metabolism , Bayes Theorem , Female , Genes, BRCA1 , Genetic Predisposition to Disease , Humans , Mutation, Missense , Ovarian Neoplasms/genetics
17.
Monaldi Arch Chest Dis ; 93(1)2022 Jun 20.
Article En | MEDLINE | ID: mdl-35723642

This study assessed the efficacy of a pulmonary rehabilitation (PR) on pulmonary and respiratory muscle function and thickness of quadriceps femoris and diaphragm of patients with post-COVID-19 syndrome. This series of cases followed nine patients who performed PR twice a week for six weeks. Patients received the following PR program: lung expansion therapy; respiratory muscle training; upper limb strength exercises; aerobic exercises on a treadmill. After the program, we observed increased peak expiratory flow (26.03%), forced vital capacity (FVC) (7.14%), forced expiratory volume in the first second (FEV1) (9.55%), and ratio between FEV1/FVC (6.19%). All parameters of respiratory muscle strength and endurance were improved. Diaphragmatic thickening fraction and thickness of quadriceps femoris also improved, whereas echo intensity of quadriceps reduced. Thus, RP protocol improved pulmonary function, respiratory muscle strength and endurance, and thickness of diaphragm and quadriceps femoris, and reduced echo intensity of quadriceps in patients with post-COVID-19 syndrome.


COVID-19 , Diaphragm , Humans , Diaphragm/diagnostic imaging , Post-Acute COVID-19 Syndrome , Quadriceps Muscle/diagnostic imaging , Lung/diagnostic imaging , Respiratory Muscles , Muscle Strength/physiology
18.
Front Pharmacol ; 13: 849136, 2022.
Article En | MEDLINE | ID: mdl-35496269

Carbamazepine triggers dermatologic hypersensitivity reactions, associated with specific human leukocyte antigens (HLAs), especially HLA-B*15:02 and HLA-A*31:01. Previous efforts to identify single nucleotide variants (SNVs) with high predictive value as HLA proxies, revealed that rs1061235 and rs17179220 fulfill these requirements for HLA-A*31:01 in some but not all populations. Herein we explored the predictive performance of rs1061235 and rs17179220 as HLA-A*31:01 tags in populations of Native American ancestry, which are largely underrepresented in pharmacogenomic studies. The study cohorts comprised the overall Admixed American superpopulation of the 1000 Genomes Project (1 KG_AMR), a subcohort of individuals with predominant Native American ancestry (1 KG_NAT), the Native American population of the Human Genome Diversity Project (HGDP), plus Kaingang (KRC) and Guarani (GRC and GKW) adults from indigenous reservation areas in Brazil. The diversity of cohorts is reflected in the range of frequencies of HLA-A*31:01 (0.02-0.65), rs1061235 (0.03-0.13) and rs17179220 (0.12-0.66), as well as in the predictive performance of these SNVs as HLA-A*31:01 proxies. NPV (negative predictive value), the metric of primary interest for pharmacogenetic-informed carbamazepine prescription was maximal (NPV = 1.0) for both SNVs in 1 KG_AMR and 1 KG_NAT, for rs17179220, but not rs1061235 (NPV = 0.91) in HGDP, and for rs17179220 in GWK, but not GRC (NPV = 0.88) or KRC (NPV = 0.80). Collectively, the data support the notion that rs1061235 and rs17179220 are not optimal proxies for HLA-A*31:01 across populations of Native American ancestry.

19.
Ecology ; 103(9): e3744, 2022 09.
Article En | MEDLINE | ID: mdl-35522227

Future climates will alter the frequency and size of rain events in drylands, potentially affecting soil microbes that generate carbon feedbacks to climate, but field tests are rare. Topsoils in drylands are commonly colonized by biological soil crusts (biocrusts), photosynthesis-based communities that provide services ranging from soil fertilization to stabilization against erosion. We quantified responses of biocrust microbial communities to 12 years of altered rainfall regimes, with 60 mm of additional rain per year delivered either as small (5 mm) weekly rains or large (20 mm) monthly rains during the summer monsoon season. Rain addition promoted microbial diversity, suppressed the dominant cyanobacterium, Microcoleus vaginatus, and enhanced nitrogen-fixing taxa, but did not consistently increase microbial biomass. The addition of many small rain events increased microbial biomass, whereas few, large events did not. These results alter the physiological paradigm that biocrusts are most limited by the amount of rainfall and instead predict that regimes enriched in small rain events will boost cyanobacterial biocrusts and enhance their beneficial services to drylands.


Microbiota , Soil , Biomass , Ecosystem , Rain , Soil Microbiology
20.
Ecology ; 103(4): e3656, 2022 04.
Article En | MEDLINE | ID: mdl-35132623

Interactions between plants and soil microbes influence plant nutrient transformations, including nitrogen (N) fixation, nutrient mineralization, and resource exchanges through fungal networks. Physical disturbances to soils can disrupt soil microbes and associated processes that support plant and microbial productivity. In low resource drylands, biological soil crusts ("biocrusts") occupy surface soils and house key autotrophic and diazotrophic bacteria, non-vascular plants, or lichens. Interactions among biocrusts, plants, and fungal networks between them are hypothesized to drive carbon and nutrient dynamics; however, comparisons across ecosystems are needed to generalize how soil disturbances alter microbial communities and their contributions to N pools and transformations. To evaluate linkages among plants, fungi, and biocrusts, we disturbed all unvegetated surfaces with human foot trampling twice yearly from 2013-2019 in dry conditions in cyanobacteria-dominated biocrusts in the Chihuahuan Desert grassland and shrubland ecosystems. After 5 years, disturbance decreased the abundances of cyanobacteria (especially Microcoleus steenstrupii clade) and N-fixers (Scytonema sp., and Schizothrix sp.) by >77% and chlorophyll a by up to 55% but, conversely, increased soil fungal abundance by 50% compared with controls. Responses of root-associated fungi differed between the two dominant plant species and ecosystem types, with a maximum of 80% more aseptate hyphae in disturbed than in control plots. Although disturbance did not affect 15 N tracer transfer from biocrusts to the dominant grass, Bouteloua eriopoda, disturbance increased available soil N by 65% in the shrubland, and decreased leaf N of B. eriopoda by up to 16%, suggesting that, although rapid N transfer during peak production was not affected by disturbance, over the long-term plant nutrient content was disrupted. Altogether, the shrubland may be more resilient to detrimental changes due to disturbance than grassland, and these results demonstrated that disturbances to soil microbial communities have the potential to cause substantial changes in N pools by reducing and reordering biocrust taxa.


Cyanobacteria , Microbiota , Chlorophyll A , Ecosystem , Fungi , Humans , Plant Leaves , Poaceae , Soil , Soil Microbiology
...