1,460 research outputs found
Foot and ankle functional morphology in anthropoid primates and Miocene hominoids
Locomotion is essential for survival in many taxa. It also varies greatly among organisms, including primates. Studying locomotor diversity in extant and fossil primates requires an understanding of form-function relationships. This is particularly true in the foot and ankle, as the foot directly contacts the substrate and tarsals are well-represented in the fossil record. Morphological differences alone provide limited aid when inferring locomotion from fossil tarsals in the absence of in vivo biomechanical consideration. This dissertation takes a three-step approach to analyze both in vivo rotations in the foot and ankle as well as morphological variation in tarsal form in extant anthropoid primates and Miocene hominoids and will provide important new data from a poorly understood anatomical region. The amount of talocrural, subtalar, and transverse tarsal rotations among the tibia, calcaneus, and navicular were visualized and quantified during the gait cycles using biplanar fluoroscopy and 3D scans of marked bones, a method known as x-ray reconstruction of moving morphology (XROMM) in rhesus macaques (Macaca mulatta). This study supported previous hypotheses that the midfoot break occurs distal to the cuboid, demonstrated the predominance of plantarflexion/dorsiflexion at the talocrural joint on a flat surface, quantified conjunct rotation at the subtalar joint, showed evidence that the transverse tarsal joint does not function as a single joint complex. Geometric morphometric techniques were used to describe and quantify shape differences in isolated tarsals of extant anthropoid primates. PCA and M/ANOVA analyses were run on a Procrustes-fit landmarks taken on broad range of anthropoid tali (n = 241), calcanei (n = 230), cuboids (n = 282), and naviculars (n = 254). In addition to the typical geometric morphometric techniques, the interlandmark distances that accounted for the greatest amount of variation in this sample were isolated and plotted against centroid size. Phylogenetically controlled generalized least squares analysis revealed which of these measurements were related to locomotion. The relative orientation of the posterior subtalar facet on the talus, talar neck length, calcaneal tuber height, calcaneal anterior length, cuboid length, and navicular anteroposterior length were the morphologies that best separated based on differences in locomotion. The same landmarks were taken on 16 Miocene hominoid tarsals in order to infer foot function based on tarsal form. The geometric morphometric technique of the extant sample allowed for subsetted analyses for incomplete fossils. Early Miocene taxa Ekembo, Proconsul, and Rangwapithecus shared common bony features that suggest that they were generally above branch quadrupeds. Nacholapithecus showed a mixed or varied locomotor behavior. Oreopithecus was shown to not be bipedal, as previously hypothesized, but rather was suspensory. This dissertation provided the first ever quantification of intertarsal and talocrural rotations in anthropoid primate feet and ankles and an analysis of how rotations within and among joints are related. It also provided a quantification of shape differences in tarsals of extant anthropoid primates and fossil Miocene hominoids. Together, the in vivo biomechanics and morphometrics provide insight into form function relationships as well as a foundation for future studies of primate locomotor diversity
Characterization in cochlea of KCTD12/PFET1, an intronless gene with predominant fetal expression
Thesis (Ph. D.)--Harvard-MIT Division of Health Sciences and Technology, February 2006."December 2005."Includes bibliographical references.The prevalence of severe to profound bilateral congenital hearing loss is estimated at 1 in 1000 births, at least half of which can be attributed to a genetic cause. To date, mutations in at least 67 genes have been associated with hearing loss. Discovery of these genes has revealed fundamental processes within the ear, and enabled diagnosis and implementation of genetic counseling in affected patients. As a part of the continuing effort to study genes important for hearing and deafness, a novel cochlear transcript with predominantly fetal expression containing a single tetramerization domain (PFET1, HUGO-approved symbol KCTD]2) was identified from the Morton fetal cochlear cDNA library. KCTD12/Kctd]2 is an evolutionarily conserved intronless gene encoding a 6 kb transcript in human and three transcripts of approximately 4, 4.5 and 6 kb in mouse. The protein, pfetin, is predicted to contain a voltage-gated potassium channel tetramerization (T1) domain. This thesis reports characterization of this novel human gene and its encoded protein pfetin in relation to its role in auditory function. Experimental data from tissue and cellular expression profiling, and genetic and functional analyses suggests KCTD12 and its orthologs playing a crucial role in the developmental of the auditory sense organ.by Sharon Fan Kuo.Ph.D
Intergenerational Transmission of Human Parenting Styles to Human–Dog Relationships
Parenting style and intergenerational transmission have been extensively studied in parent–child relationships. As dogs are increasingly recognized as integral members of the family system, there is a growing interest in understanding how parenting behaviors directed towards dogs can also influence a dog’s behaviors. However, the reasons why people adopt certain parenting behaviors towards dogs remain relatively unknown. This study delved into the intergenerational transmission of parenting styles from one’s upbringing to caregiving for dogs. Using a mixed methods approach with 391 dog caregivers and 10 interviews, this study employed multivariate linear regression and thematic analysis. Permissive parenting exhibited an intergenerational effect, with those experiencing it being more likely to replicate the style with their dogs. Orientation towards dogs emerged as a crucial mediator, with protectionistic attitudes reducing the likelihood of replicating authoritarianparenting. Humanistic and protectionistic orientation increased the likelihood of compensatory permissive behaviors. Insights from interviews underscored the impact of perceived childhood experiences on adopting specific parenting behaviors. Ultimately, this study provides valuable insights that can contribute to the promotion of appropriate caregiving behaviors toward dogs. By drawing on our understanding of child–parent relationships, addressing the underlying elements of human–dog dynamics may lead to positive outcomes both for dogs and their caregivers
Serum Homocysteine and Intracranial Aneurysms
Subarachnoid haemorrhage (SAH) occurs as a result of rupture of intracranial aneurysms. SAH causes significant morbidity and mortality. In addition, SAH leads to significant financial burden. In this chapter, we will look into the association between raised serum homocysteine and intracranial aneurysms. In a study on the Han Chinese patients with intracranial aneurysm who were admitted to the hospital, the mean serum total homocysteine level in the patient group with intracranial aneurysm was significantly higher than those in the control group. In the same study, the patients with raised serum homocysteine had 2.196 higher risk of developing intracranial aneurysms. Ren et al. proposed that homocysteine should be seen as an indicator of the risk of intracranial aneurysm and not a direct cause of intracranial aneurysm. In another study, homocysteine increases the development of intracranial aneurysms in rats. Endothelial damage is an early change in the walls of intracranial aneurysms. Polymorphisms of the genes coding for the various components of the vessel walls may be associated with the formation of intracranial aneurysms. In a previous animal study, the size of intracranial aneurysms is significantly smaller in the mice with inducible nitric oxide synthase (iNOS) compared with the mice without iNOS
Critical Intersections through Poetry in a TESOL & World Language Graduate Education Program
In this studio submission, Language Education students who took one or more poetry writing courses along with their instructor share one poem draft and critical reflection, noting the political climate of the work co-produced and inquiry regarding the impact of producing creative work as reflexive, critical teacher education scholarship. Together they draw a context and implications for creative and critical teacher education through shared poetry writing
Atherosclerosis at Extracranial Carotid Vessels and Serum Homocysteine
In this chapter we will discuss more about the role of homocysteine in atherosclerosis and also association between serum homocysteine with extracranial carotid atherosclerosis. Carotid atherosclerosis comprises an increase in carotid intima-media (CIMT) thickening, plaque formation and carotid stenosis. Atherogenic property of homocysteine was discovered in 1969. Atherosclerosis is initiated by endothelial dysfunction. One of the causes of endothelial abnormality is homocysteine. The development of aggregates of homocysteinylated lipoproteins with microorganisms obstructs the vasa vasorum in vulnerable plaques. In one study, serum homocysteine in the highest quartile was independently associated with extracranial carotid artery stenosis ≥50%. In another study, raised serum homocysteine was also independently associated with severe extracranial carotid stenosis in both genders. In other studies, serum homocysteine was significantly associated with carotid artery stenosis in internal carotid arteries and external carotid arteries as well as the degree of stenosis. The hypertensive patients who had raised serum homocysteine were reported to have higher risk of developing asymptomatic extracranial carotid artery stenosis
Cluster abundances and S-Z power spectra: effects of non-Gaussianity and early dark energy
In the standard Lambda CDM cosmological model with a Gaussian primordial
density fluctuation field, the relatively low value of the mass variance
parameter (sigma_8=0.74{+0.05}{-0.06}, obtained from the WMAP 3-year data)
results in a reduced likelihood that the measured level of CMB anisotropy on
the scales of clusters is due to the Sunyaev-Zeldovich (S-Z) effect. To assess
the feasibility of producing higher levels of S-Z power, we explore two
alternative models which predict higher cluster abundance. In the first model
the primordial density field has a chi^2_1 distribution, whereas in the second
an early dark energy component gives rise to the desired higher cluster
abundance. We carry out the necessary detailed calculations of the levels of
S-Z power spectra, cluster number counts, and angular 2-point correlation
function of clusters, and compare (in a self-consistent way) their predicted
redshift distributions. Our results provide a sufficient basis upon which the
viability of the three models may be tested by future high quality
measurements.Comment: 12 pages, 5 figures, accepted for publication in MNRA
Association of Cancer Diagnosis With Disability Status among Older Survivors of Colorectal Cancer: a Population-Based Retrospective Cohort Study
BACKGROUND: Older cancer survivors likely experience physical function limitations due to cancer and its treatments, leading to disability and early mortality. Existing studies have focused on factors associated with surgical complications and mortality risk rather than factors associated with the development of poor disability status (DS), a proxy measure of poor performance status, in cancer survivors. We aimed to identify factors associated with the development of poor DS among older survivors of colorectal cancer (CRC) and compare poor DS rates to an age-sex-matched, non-cancer cohort.
METHODS: This retrospective cohort study utilized administrative data from the Texas Cancer Registry Medicare-linked database. The study cohort consisted of 13,229 survivors of CRC diagnosed between 2005 and 2013 and an age-sex-matched, non-cancer cohort of 13,225 beneficiaries. The primary outcome was poor DS, determined by Davidoff\u27s method, using predictors from 12 months of Medicare claims after cancer diagnosis. Multivariable Cox proportional hazards regression was used to identify risk factors associated with the development of poor DS.
RESULTS: Among the survivors of CRC, 97% were 65 years or older. After a 9-year follow-up, 54% of survivors of CRC developed poor DS. Significant factors associated with future poor DS included: age at diagnosis (hazard ratio [HR] = 3.50 for \u3e80 years old), female sex (HR = 1.50), race/ethnicity (HR = 1.34 for Hispanic and 1.21 for Black), stage at diagnosis (HR = 2.26 for distant metastasis), comorbidity index (HR = 2.18 for \u3e1), and radiation therapy (HR = 1.21). Having cancer (HR = 1.07) was significantly associated with developing poor DS in the pooled cohorts; age and race/ethnicity were also significant factors.
CONCLUSIONS: Our findings suggest that a CRC diagnosis is independently associated with a small increase in the risk of developing poor DS after accounting for other known factors. The study identified risk factors for developing poor DS in CRC survivors, including Hispanic and Black race/ethnicity, age, sex, histologic stage, and comorbidities. These findings underscore the importance of consistent physical function assessments, particularly among subsets of older survivors of CRC who are at higher risk of disability, to prevent developing poor DS
Venue-Based Recruitment of Women at Elevated Risk for HIV: An HIV Prevention Trials Network Study
Background: The challenge of identifying and recruiting U.S. women at elevated risk for HIV acquisition impedes prevention studies and services. HIV Prevention Trials Network (HPTN) 064 was a U.S. multisite, longitudinal cohort study designed to estimate HIV incidence among women living in communities with prevalent HIV and poverty. Venue-based sampling (VBS) methodologies and participant and venue characteristics are described.
Methods: Eligible women were recruited from 10 U.S. communities with prevalent HIV and poverty using VBS. Participant eligibility criteria included age 18–44 years, residing in a designated census tract/zip code, and self-report of at least one high-risk personal and/or male sexual partner characteristic associated with HIV acquisition (e.g., incarceration history). Ethnography was conducted to finalize recruitment areas and venues.
Results: Eight thousand twenty-nine women were screened and 2,099 women were enrolled (88% black, median age 29 years) over 14 months. The majority of participants were recruited from outdoor venues (58%), retail spaces (18%), and social service organizations (13%). The proportion of women recruited per venue category varied by site. Most participants (73%) had both individual and partner characteristics that qualified them for the study; 14% were eligible based on partner risk only.
Conclusion: VBS is a feasible and effective approach to rapidly recruit a population of women at enhanced risk for HIV in the United States. Such a recruitment approach is needed in order to engage women most at risk and requires strong community engagement
Dendritic glycopolymers based on dendritic polyamine scaffolds: view on their synthetic approaches, characteristics and potential for biomedical applications
In this review we highlight the potential for biomedical applications of dendritic glycopolymers based on polyamine scaffolds. The complex interplay of the molecular characteristics of the dendritic architectures and their specific interactions with various (bio)molecules are elucidated with various examples. A special role of the individual sugar units attached to the dendritic scaffolds and their density is identified, which govern ionic and H-bond interactions, and biological targeting, but to a large extent are also responsible for the significantly reduced toxicity of the dendritic glycopolymers compared to their polyamine scaffolds. Thus, the application of dendritic glycopolymers in drug delivery systems for gene transfection but also as therapeutics in neurodegenerative diseases has great promisePublikacja w ramach programu Royal Society of Chemistry "Gold for Gold" 2014 finansowanego przez Uniwersytet Łódzk
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