710 research outputs found
Physiological stress in eastern black rhinoceros (Diceros bicornis michaeli) as influenced by their density, climatological variables and sexes
It is important to understand the physiological stressors in animals especially for threatened species or intensively managed to improve their conservation and optimise their reproduction. We sought to understand changes in stress hormones (faecal glucocorticoid metabolites) in black rhinoceros (Diceros bicornis michaeli) in relation to population density and sex (intrinsic factors) and plant minerals, rainfall and land surface temperature (extrinsic factors). We used non-invasive faecal sampling techniques on animals of known sex, age and dominance in seven populations of contrasting population densities over 1âyear. We measured variability in faecal corticosterone metabolites through radioimmunoassay and related them to population density, sex and faecal calcium, phosphorus, copper, zinc and potassium as characteristic of plant minerals, rainfall and temperature. We used linear mixed models (LMM) to analyse the data. We did not detect a significant relationship between physiological stress parameters and population density. However, we have indications that stress levels increased as rainfall and temperature increased and were correlated negatively and positively with concentration of faecal phosphorus and copper respectively; we found higher stress levels in females than in males. These results suggest that both intrinsic and extrinsic factors explain the variation in physiological stress observed in black rhinoceros
Differences in branch characteristics of Scots pine (Pinus sylvestris L.) genetic entries grown at different spacing
âą We studied the differences in branch characteristics along the stems of six different
genetic entries of 20 year old Scots pines (Pinus sylvestris L.) grown at
different spacing (current stand density range 2000â4000 trees haâ1) in central
Finland. Furthermore, we studied the phenotypic correlations between yield, wood density
traits and branch characteristics. All the genetic entries had Kanerva pine (plus tree
S1101) as a father tree, whereas the mother tree represented Finnish plus trees from
southern, central and northern Finland.
âą Spacing affected all yield traits, wood density and living branch characteristics such
as relative average branch diameter and relative cumulative branch area
(p < 0.05). As a comparison, genetic entry affected height,
while origin group (southern, central and northern ones) affected most of the studied
traits. Regardless of spacing, the northern origin had, on average, the largest stem
diameter and highest wood density, while the central one was the tallest one. Furthermore,
average branch diameter along the stem was affected by branch age, origin group and
spacing, while average branch angle was affected by branch age and genetic entry
(p < 0.05).
âą In general the average branch size could be decreased especially in lower tree canopy
by denser spacing during the early phase of the rotation, but only at the expense of tree
growth. Correspondingly differences between origins are mainly related to their
differences in stem growth
Power Law Scaling for a System of Interacting Units with Complex Internal Structure
We study the dynamics of a system composed of interacting units each with a
complex internal structure comprising many subunits. We consider the case in
which each subunit grows in a multiplicative manner. We propose a model for
such systems in which the interaction among the units is treated in a mean
field approximation and the interaction among subunits is nonlinear. To test
the model, we identify a large data base spanning 20 years, and find that the
model correctly predicts a variety of empirical results.Comment: 4 pages with 4 postscript figures (uses Revtex 3.1, Latex2e,
multicol.sty, epsf.sty and rotate.sty). Submitted to PR
Bioelectrical Impedance Analysis and Mid-Upper Arm Muscle Circumference Can Be Used to Detect Low Muscle Mass in Clinical Practice
Identification of low muscle mass becomes increasingly relevant due to its prognostic value in cancer patients. In clinical practice, mid-upper arm muscle circumference (MAMC) and bioelectrical impedance analysis (BIA) are often used to assess muscle mass. For muscle-mass assessment, computed tomography (CT) is considered as reference standard. We investigated concordance between CT, BIA, and MAMC, diagnostic accuracy of MAMC, and BIA to detect low muscle mass and their relation with the clinical outcome malnutrition provided with the Patient-Generated Subjective Global Assessment Short Form (PG-SGA SF). This cross-sectional study included adult patients with advanced esophageal and gastrointestinal cancer. BIA, MAMC, and PG-SGA-SF were performed. Routine CT-scans were used to quantify psoas muscle index (PMI) and skeletal muscle area. Good concordance was found between CT(PMI) and both BIA(FFMI (fat free mass index)) (ICC 0.73), and BIA(ASMI (appendicular skeletal muscle index)) (ICC 0.69) but not with MAMC (ICC 0.37). BIA(FFMI) (94%), BIA(ASMI) (86%), and MAMC (86%) showed high specificity but low sensitivity. PG-SGA-SF modestly correlated with all muscle-mass measures (ranging from â0.17 to â0.43). Of all patients with low muscle mass, 62% were also classified with a PG-SGA-SF score of â„4 points. Although CT remains the first choice, since both BIA and MAMC are easy to perform by dieticians, they have the potential to be used to detect low muscle mass in clinical practice
Galactosialidosis: Nueva mutaciĂłn de novo en el gen CTSA en un paciente afecto de la forma infantil tardĂa
La galactosialidosis (OMIM #256540) es una enfermedad metabĂłlica lisosomal causada por mutaciones en el gen CTSA, que codifica la proteĂna protectora catepsina A. La pĂ©rdida de funciĂłn de dicha proteĂna causa, secundariamente, un dĂ©ficit combinado de dos enzimas, beta-galactosidasa y neuraminidasa. Se expone el caso de un paciente que presentĂł manifestaciones clĂnicas compatibles con el subtipo infantil tardĂo de galactosialidosis. El anĂĄlisis bioquĂmico mostrĂł dĂ©ficits de las dos enzimas implicadas, mientras que el estudio molecular revelĂł dos mutaciones: una nueva mutaciĂłn nunca antes descrita, p.His475Pro (c.1424 A>C), y una mutaciĂłn previamente reportada, p.Arg441Cys (c.1321C>T), localizadas en los exones 15 y 14, respectivamente. Galactosialidosis (OMIM #256540) is an autosomal recessive lysosomal storage disorder caused by mutations in the CTSA gene, which encodes the protective protein cathepsin A. The loss of function of this protein causes a secondarily deficiency of beta-galactosidase and N-acetyl-ĂĄ-neuraminidase enzymes activities. We describe the clinical, biochemical and molecular analysis of a case report with a phenotype compatible with the late infantile form. The biochemical analysis reveled deficiencies of beta-galactosidase and neuraminidase activities in dried blood spot and fibroblasts and the molecular study showed two missense mutations in the CTSA gene: A previously reported mutation, p.Arg441Cys (c.1321C>T), and a novel mutation, p.His475Pro (c.1424 A>C), located in exons 14 and 15, respectively
Expression of the RNA helicase DDX3 and the hypoxia response in breast cancer
<p>Aims: DDX3 is an RNA helicase that has antiapoptotic properties, and promotes proliferation and transformation. In addition, DDX3 was shown to be a direct downstream target of HIF-1α (the master regulatory of the hypoxia response) in breast cancer cell lines. However, the relation between DDX3 and hypoxia has not been addressed in human tumors. In this paper, we studied the relation between DDX3 and the hypoxic responsive proteins in human breast cancer.</p>
<p>Methods and Results: DDX3 expression was investigated by immunohistochemistry in breast cancer in comparison with hypoxia related proteins HIF-1α, GLUT1, CAIX, EGFR, HER2, Akt1, FOXO4, p53, ERα, COMMD1, FER kinase, PIN1, E-cadherin, p21, p27, Transferrin receptor, FOXO3A, c-Met and Notch1. DDX3 was overexpressed in 127 of 366 breast cancer patients, and was correlated with overexpression of HIF-1α and its downstream genes CAIX and GLUT1. Moreover, DDX3 expression correlated with hypoxia-related proteins EGFR, HER2, FOXO4, ERα and c-Met in a HIF-1α dependent fashion, and with COMMD1, FER kinase, Akt1, E-cadherin, TfR and FOXO3A independent of HIF-1α.</p>
<p>Conclusions: In invasive breast cancer, expression of DDX3 was correlated with overexpression of HIF-1α and many other hypoxia related proteins, pointing to a distinct role for DDX3 under hypoxic conditions and supporting the oncogenic role of DDX3 which could have clinical implication for current development of DDX3 inhibitors.</p>
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