scholarly journals Variations in First Union Dissolution Patterns among the Lebou, Peuhl, Sereer, Toucouleur, and Wolof in Senegal

2021 ◽  
Author(s):  
Justin Dansou
Keyword(s):  
Ethnic Groups ◽  
Specific Effect ◽  
Union Dissolution ◽  
Kaplan Meier ◽  
First Union ◽  
Marital Outcomes ◽  
Sub Saharan ◽  
Underlying Mechanisms ◽  
The Stability ◽  
Ethnic Variations

Major changes have been observed in recent decades both in the mode of union formation and in the stability of conjugal unions in Sub-Saharan Africa. Although these changes are known to vary in intensity across countries, variations across ethnical groups within countries are still not well studied. The present study investigates ethnic variations in the dissolution of first union in Senegal, focusing on five ethnic groups: Lebou, Peuhl, Sereer, Toucouleur and Wolof. It attempts to examine the specific effect of ethnicity and to identify underlying mechanisms of action of ethnic variations in union dissolution among men and women. The study uses data from a biographical survey on “vulnerabilities and chronic poverty” in Senegal (2008-2009) and event history analysis techniques. Kaplan-Meier survivor functions were used to explore bivariate relationships and Cox semi-parametric hazard model for multivariate analysis. Results showed that ethnic differences in the hazard of union dissolution become apparent only after controlling for the effects of cumulated fertility, education and birth cohort highlighting the persistence of cultural differences between ethnic groups that cannot be explained by only standard sociological and demographic variables. Ethnicity practices continue to shape marital outcomes in Senegal, especially after controlling for other covariates. This study suggests the need for large-scale and more detailed data covering all Senegalese ethnic groups for a better understanding of the complexity and the persistence of domestic and matrimonial customs and traditions in matrimonial relationships.

scholarly journals Fine scale human genetic structure in three regions of Cameroon reveals episodic diversifying selection

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kevin K. Esoh ◽  
Tobias O. Apinjoh ◽  
Steven G. Nyanjom ◽  
Ambroise Wonkam ◽  
Emile R. Chimusa ◽  
...  
Keyword(s):  
Genetic Structure ◽  
Ethnic Groups ◽  
Genetic Association ◽  
Association Studies ◽  
Genetic Association Studies ◽  
Genomic Region ◽  
Sub Saharan Africa ◽  
Genome Wide Association Studies ◽  
Fine Scale ◽  
Sub Saharan

AbstractInferences from genetic association studies rely largely on the definition and description of the underlying populations that highlight their genetic similarities and differences. The clustering of human populations into subgroups (population structure) can significantly confound disease associations. This study investigated the fine-scale genetic structure within Cameroon that may underlie disparities observed with Cameroonian ethnicities in malaria genome-wide association studies in sub-Saharan Africa. Genotype data of 1073 individuals from three regions and three ethnic groups in Cameroon were analyzed using measures of genetic proximity to ascertain fine-scale genetic structure. Model-based clustering revealed distinct ancestral proportions among the Bantu, Semi-Bantu and Foulbe ethnic groups, while haplotype-based coancestry estimation revealed possible longstanding and ongoing sympatric differentiation among individuals of the Foulbe ethnic group, and their Bantu and Semi-Bantu counterparts. A genome scan found strong selection signatures in the HLA gene region, confirming longstanding knowledge of natural selection on this genomic region in African populations following immense disease pressure. Signatures of selection were also observed in the HBB gene cluster, a genomic region known to be under strong balancing selection in sub-Saharan Africa due to its co-evolution with malaria. This study further supports the role of evolution in shaping genomes of Cameroonian populations and reveals fine-scale hierarchical structure among and within Cameroonian ethnicities that may impact genetic association studies in the country.

scholarly journals Nonlinear Blade Stability for a Scaled Autogyro Rotor at High Advance Ratios

2020 ◽  
Vol 65 (1) ◽  
pp. 1-19
Author(s):  
Djamel Rezgui ◽  
Mark H. Lowenberg
Keyword(s):  
High Speed ◽  
Flow Speed ◽  
Numerical Continuation ◽  
Control Input ◽  
Nonlinear Phenomenon ◽  
Scaled Model ◽  
Underlying Mechanisms ◽  
Slowed Rotor ◽  
The Stability ◽  
Blade Pitch Angle

Despite current research advances in aircraft dynamics and increased interest in the slowed rotor concept for high-speed compound helicopters, the stability of autogyro rotors remains partially understood, particularly at lightly loaded conditions and high advance ratios. In autorotation, the periodic behavior of a rotor blade is a complex nonlinear phenomenon, further complicated by the fact that the rotor speed is not held constant. The aim of the analysis presented in this article is to investigate the underlying mechanisms that can lead to rotation-flap blade instability at high advance ratios for a teetering autorotating rotor. The stability analysis was conducted via wind tunnel tests of a scaled autogyro model combined with numerical continuation and bifurcation analysis. The investigation assessed the effect of varying the flow speed, blade pitch angle, and rotor shaft tilt relative to the flow on the rotor performance and blade stability. The results revealed that rotor instability in autorotation is associated with the existence of fold bifurcations, which bound the control-input and design parameter space within which the rotor can autorotate. This instability occurs at a lightly loaded condition and at advance ratios close to 1 for the scaled model. Finally, it was also revealed that the rotor inability to autorotate was driven by blade stall.

scholarly journals GnasR201C Induces Murine Pancreatic Cystic Neoplasms through Suppression of YAP1 Signaling and Transcriptional Reprogramming

2018 ◽  
Author(s):  
Noboru Ideno ◽  
Hiroshi Yamaguchi ◽  
Bidyut Ghosh ◽  
Sonal Gupta ◽  
Takashi Okumura ◽  
...  
Keyword(s):  
Protein A ◽  
Ductal Adenocarcinoma ◽  
Cystic Neoplasms ◽  
Transcriptional Reprogramming ◽  
Kaplan Meier ◽  
Stimulatory G Protein ◽  
Kinase Cascade ◽  
Well Differentiated ◽  
Underlying Mechanisms ◽  
Pancreatic Neoplasia

ABSTRACTBackground & AimsSomatic “hotspot” mutations of GNAS, which encodes for the alpha subunit of stimulatory G-protein, are present in ~60% of intraductal papillary mucinous neoplasms (IPMNs) of the pancreas. There are currently no cognate animal models that recapitulate the biology of mutant Gnas-induced IPMNs, and the underlying mechanisms that lead to the cystic pathway of neoplasia in the pancreas remain unknown.MethodsWe generated p48-Cre; LSL-KrasG12D; Rosa26R-LSL-rtTA-TetO-GnasR201C mice (Kras; Gnas mice) where pancreas-specific GnasR201C expression was induced by doxycycline administration. In this model, mutant Kras is constitutively expressed, and control mice were produced through absence of doxycycline. Separate cohorts of mice were utilized for timed necropsies and for Kaplan-Meier survival analysis. Isogenic cell lines (with doxycycline inducible mutant Gnas expression) were propagated from the resulting pancreatic ductal adenocarcinoma (PDAC).ResultsCo-expression of KrasG12D and GnasR201C resulted in the development of pancreatic cystic lesions resembling human IPMNs in 100% of mice, with higher grades of epithelial dysplasia observed over time. Approximately one-third of Kras; Gnas mice developed PDAC at a median of 38 weeks post doxycycline induction. GnasR201C did not accelerate oncogenic transformation with KrasG12D, but rather, reprogrammed Ras-induced neoplasms towards a well-differentiated phenotype. GnasR201C induction led to activation of the inhibitory Hippo kinase cascade and cytoplasmic sequestration of phosphorylated YAP1 protein, a phenomenon that was also observed in human IPMN with GNAS mutations.ConclusionsGNASR201C functions not as a traditional oncogene, but rather as an “oncomodulator” of KRAS-mediated pancreatic neoplasia, through suppression of YAP1 and transcriptional reprogramming towards a differentiated (large ductal) phenotype.

scholarly journals The collapse of genetic incompatibilities in a hybridizing population

2021 ◽  
Author(s):  
Tianzhu Xiong ◽  
James L MALLET
Keyword(s):  
Gene Regulation ◽  
Reproductive Isolation ◽  
Genetic Drift ◽  
Recombination Rate ◽  
Time Scale ◽  
Genetic Incompatibility ◽  
Genetic Process ◽  
Underlying Mechanisms ◽  
The Stability

Genetic incompatibility has long been considered to be a hallmark of speciation due to its role in reproductive isolation. Previous analyses of the stability of epistatic incompatibility show that it is subject to collapse upon hybridization. In the present work, we derive explicitly the distribution of the lifespan of two-locus incompatibilities, and show that genetic drift, along with recombination, is critical in determining the time scale of collapse. The first class of incompatibilities, where derived alleles separated in parental populations act antagonistically in hybrids, survive longer in smaller populations when incompatible alleles are (co)dominant and tightly linked, but collapse more quickly when they are recessive. The second class of incompatibilities, where fitness is reduced by disrupting co-evolved elements in gene regulation systems, collapse on a time scale proportional to the exponential of effective recombination rate. Overall, our result suggests that the effects of genetic drift and recombination on incompatibility's lifespan depend strongly on the underlying mechanisms of incompatibilities. As the time scale of collapse is usually shorter than the time scale of establishing a new incompatibility, the observed level of genetic incompatibilities in a particular hybridizing population may be shaped more by the collapse than by their initial accumulation. Therefore, a joint theory of accumulation-erosion of incompatibilities is in need to fully understand the genetic process under speciation with hybridization.

scholarly journals Ethnic Differences in Antipsychotic treatment responses in Early Intervention in Psychosis

The Physician ◽  
2021 ◽  
Vol 7 (1) ◽  
pp. 1-8
Author(s):  
Nandini Chakraborty ◽  
Shiraz Ahmed ◽  
Hannah Booth ◽  
Hawa Aswat
Keyword(s):  
Early Intervention ◽  
Ethnic Group ◽  
Ethnic Groups ◽  
Ethnic Differences ◽  
Antipsychotic Treatment ◽  
Electronic Patient Records ◽  
Treatment Responses ◽  
Ethnic Variations ◽  
Early Intervention In Psychosis ◽  
Best Responses

Background Ethnic variations in pathways to early intervention in psychosis (EIP) have been studied. However, it is important to explore the ethnic variations in response to pharmacological treatment in EIP. Aims To look at ethnic variation in response to antipsychotics. Method Electronic patient records in December 2018 were perused for: Sociodemographic details including ethnicity Prescribed antipsychotic and dosage to which the patient had responded Results White, Black and Asian ethnic groups responded mostly to Olanzapine. The largest proportion of the mixed ethnic group responded to Aripiprazole. The White and Asian groups showed the best responses to Lurasidone at 74 mg. There was a slight response in the mixed and other ethnic groups only at the higher dose of 111 mg. The medication has not been used with any benefit in the Black ethnic group. Conclusion The complex differences highlighted amongst ethnic responses to treatment make a case for multi-centric studies to further explore ethnic differences in early intervention treatments. This will help streamline offered treatments to maximise response in EIP.

scholarly journals Predictors of three-month mortality among hospitalized older adults in Togo

2020 ◽  
Author(s):  
Fifonsi Adjidossi GBEASOR-KOMLANVI ◽  
Martin Kouame TCHANKONI ◽  
Akila Wimima BAKOUBAYI ◽  
Matthieu Yaovi LOKOSSOU ◽  
Arnold SADIO ◽  
...  
Keyword(s):  
Older Adults ◽  
Hospital Mortality ◽  
Cox Regression ◽  
Sub Saharan Africa ◽  
Mortality Data ◽  
Kaplan Meier ◽  
All Cause Mortality ◽  
Hospitalized Older Adults ◽  
Sub Saharan

Abstract Background: Assessing hospital mortality and its predictors is important as some of these can be prevented through appropriate interventions. Few studies have reported hospital mortality data among older adults in sub-Saharan Africa. The objective of this study was to assess the mortality and associated factors among hospitalized older adults in Togo.Methods: We conducted a prospective cohort study from February 2018 to September 2019 among patients ≥50 years admitted in medical and surgical services of six hospitals in Togo. Data were recorded during hospitalization and through telephone follow-up survey within 90 days after admission. The main outcome was all-cause mortality at 3 months. Survival curves were estimated using the Kaplan-Meier method and Cox regression analyses were performed to assess predictors of mortality.Results: The median age of the 650 older adults included in the study period was 61 years, IQR: [55-70] and at least one comorbidity was identified in 59.7% of them. The all-cause mortality rate of 17.2% (95%CI: 14.4-20.4) and the majority of death (93.7%) occurred in hospital. Overall survival rate was 85.5% and 82.8% after 30 and 90 days of follow-up, respectively. Factors associated with 3-month mortality were the hospital level in the health pyramid, hospitalization service, length of stay, functional impairment, depression and malignant diseases.Conclusion: Togolese health system needs to adjust its response to an aging population in order to provide the most effective care.

INTERACTION OF DOMINANT PARTY WITH ETHNIC GROUPS IN COMPETITIVE AUTHORITARIANISM IN MALAYSIA

2020 ◽  
Vol 14 (3) ◽  
pp. 107-113
Author(s):  
Tatiana Lavrova ◽  
Keyword(s):  
Ethnic Groups ◽  
Historical Context ◽  
The State ◽  
Power Sharing ◽  
Competitive Authoritarianism ◽  
Dominant Party ◽  
State Apparatus ◽  
The Status ◽  
The Stability ◽  
And Control

The author covers the question of the stability of competitive authoritarianism in Malaysia. In this case, such a regime is particularly stable, possibly due to the developed and institutionalized model of interaction between the dominant party and ethnic groups, implemented in the conditions of the polyethnic composition of the state. It was crucial to take into account the historical context of the British colonization of Malaysia, which had led to the influx of migrants, and the presence of a political party in power for 61 years, which was practically merged with the state apparatus and fully represented only one ethnic group. "Ethnic outbidding" implemented by the dominant party UMNO provided a numerically greater population with benefits in exchange for support of the ruling party. Simultaneously, the incorporation of ethnic groups into the state's political structure and the use of the power-sharing model allowed UMNO to act as an umbrella party and to maintain the status quo. The unspoken Treaty, first, was based on granting the privilege to the indigenous Malay population, and, second, protected the interests of non-Malays. Thus, granting bumiputera and non-Malays certain privileges, the establishment was able to consolidate a non-democratic regime and control over complex Malaysian society.

scholarly journals Dual functions of Rack1 in regulating Hedgehog pathway

2020 ◽  
Vol 27 (11) ◽  
pp. 3082-3096 ◽  
Author(s):  
Yan Li ◽  
Xiaohan Sun ◽  
Dongqing Gao ◽  
Yan Ding ◽  
Jinxiao Liu ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Cellular Localization ◽  
Multiple Roles ◽  
Dual Roles ◽  
Cubitus Interruptus ◽  
Trimeric Complex ◽  
Physiological Processes ◽  
Underlying Mechanisms ◽  
The Stability ◽  
Fine Tune

Abstract Hedgehog (Hh) pathway plays multiple roles in many physiological processes and its dysregulation leads to congenital disorders and cancers. Hh regulates the cellular localization of Smoothened (Smo) and the stability of Cubitus interruptus (Ci) to fine-tune the signal outputs. However, the underlying mechanisms are still unclear. Here, we show that the scaffold protein Rack1 plays dual roles in Hh signaling. In the absence of Hh, Rack1 promotes Ci and Cos2 to form a Ci–Rack1–Cos2 complex, culminating in Slimb-mediated Ci proteolysis. In the presence of Hh, Rack1 dissociates from Ci–Rack1–Cos2 complex and forms a trimeric complex with Smo and Usp8, leading to Smo deubiquitination and cell surface accumulation. Furthermore, we find the regulation of Rack1 on Hh pathway is conserved from Drosophila to mammalian cells. Our findings demonstrate that Rack1 plays dual roles during Hh signal transduction and provide Rack1 as a potential drug target for Hh-related diseases.

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