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Major depressive disorder is often linked to stress. Although short-term stress is without effect in mice, prolonged stress leads to depressive-like behavior, indicating that an allostatic mechanism exists in this difference. Here we demonstrate that mice after short-term (1 h per day for 7 days) chronic restraint stress (CRS), do not display depressive-like behavior. Analysis of the hippocampus of these mice showed increased levels of neurotrophic factor-α1 (NF-α1; also known as carboxypeptidase E, CPE), concomitant with enhanced fibroblast growth factor 2 (FGF2) expression, and an increase in neurogenesis in the dentate gyrus. In contrast, after prolonged (6 h per day for 21 days) CRS, mice show decreased hippocampal NF-α1 and FGF2 levels and depressive-like responses. In NF-α1-knockout mice, hippocampal FGF2 levels and neurogenesis are reduced. These mice exhibit depressive-like behavior that is reversed by FGF2 administration. Indeed, studies in cultured hippocampal neurons reveal that NF-α1 treatment directly upregulates FGF2 expression through extracellular signal-regulated kinase-Sp1 signaling. Thus, during short-term CRS, hippocampal NF-α1 expression is upregulated and has a key role in preventing the onset of depressive-like behavior through enhanced FGF2-mediated neurogenesis. To evaluate the therapeutic potential of this pathway, we examined, rosiglitazone (Rosi), a PPARγ agonist, which has been shown to have antidepressant activity in rodents and humans. Rosi upregulates FGF2 expression in a NF-α1-dependent manner in hippocampal neurons. Mice fed Rosi show increased hippocampal NF-α1 levels and neurogenesis compared with controls, thereby indicating the antidepressant action of this drug. Development of drugs that activate the NF-α1/FGF2/neurogenesis pathway can offer a new approach to depression therapy.

•Rotavirus positivity reported from India is 26.4% (range 10.3–52.5%).•Children under the age of two years account for 69.7% of rotavirus positive diarrhea.•Maximum number of rotavirus related hospitalizations are reported between months, November to March. Rotavirus is the leading cause of severe, dehydrating diarrhea in children aged <5 years globally, with an estimated 25 million outpatient visits and 2 million hospitalizations attributable to rotavirus infections each year. The aim of this hospital-based surveillance was to summarize the local epidemiological and virological features of rotavirus and to estimate the disease burden in the population under surveillance in India. During the 16 months surveillance period from April 2011 through July 2012, a total of 4711 children under the age of 5 years were admitted with acute diarrhea at 12 medical centers attached to medical schools throughout India. Stool samples were randomly collected from 2051 (43.5%) subjects and were analyzed for rotavirus positivity using commercial enzyme immunoassay kit (Premier Rotaclone Qualitative Elisa) at the respective study centers. Rotavirus positive samples were genotyped for VP7 and VP4 by reverse-transcription polymerase chain reaction (RT-PCR) at a central laboratory. During the study period, maximum number of rotavirus related hospitalizations were reported from December 2011 through February 2012. Out of the 2051 stool samples tested for rotavirus, overall 541 (26.4%) samples were positive for rotavirus VP6 antigen in stool. The highest positivity was observed in the month of December, 2011 (52.5%) and lowest in the month of May, 2011 (10.3%). We found that majority of the rotavirus positive cases (69.7%) were in children <24 months of age. The most common genotypes reported were G1 (38%), G2 (18%), G9 (18%), G12 (9%) and mixed strains (17%). The results of this study confirm the significant burden of acute rotavirus gastroenteritis as a cause of hospitalizations in under five children in India.

The singularity of the sharp V-notch problems changes with the change in notch angle. It is not possible to employ quarter-point elements (QPEs) for the analysis of sharp V-notches, as they provide only the inverse square root singularity. If QPEs are also used for notches, then a unified analysis of notches and cracks can be performed with less computational cost. In the present work, for the very first time, an attempt is made to use the QPEs to compute the notch stress intensity factors (NSIFs) of sharp V-notch problems. To this end, a point substitution technique is proposed for the calculation of mixed-mode (I/II) NSIFs using the QPEs at the notch tip. Certain critical points are identified on the QPEs along the notch flanks using the proposed technique. Utilizing finite element displacements at these critical points, the mixed-mode NSIFs are computed on coarse meshes. The results for several mode I, mode II and mixed-mode (I/II) benchmark example problems clearly show excellent agreement with the published solutions and provide a way to employ the QPEs in sharp V-notch problems.

The present work aims to investigate the effect of adding carbon nanotubes (CNTs) to epoxy on enhancing the resistance to growth of an existing embedded delamination in post-impact loading in a carbon/CNT + epoxy laminate. 3D finite element analyses are performed to determine the interlaminar stresses and strain energy release rate components at the elliptical delamination front which is elliptical using Irwin’s crack closure integral. Results show that a significant increase in resistance to growth of embedded elliptical delamination could be achieved by mixing CNTs to epoxy limited to a specific weight percentage of CNTs only.

Damage tolerance principles are widely used to assess the structural integrity and failure of engineering components. The advances in numerical simulation techniques facilitate the prediction of fatigue life of engineering component, which is essential in damage tolerance design. For the components under mixed mode (I/II) loading, the fatigue crack growth and life is predicted by using a modified form of Paris' law along with the equivalent stress intensity factor (Δ K eq ). Numerous Δ K eq models are available for correlating the equivalent stress intensity factor range and the fatigue crack growth rate. The knowledge of proper Δ K eq model is essential for the accurate fatigue life estimation. In this work, the authors numerically assess the performance of Δ K eq models in mixed mode fatigue life prediction with the help of published experimental mixed mode data.

In this paper, determination of the accurate notch stress intensity factors (NSIFs) have been demonstrated using a recently proposed technique: The point substitution displacement technique (PSDT) for the sharp Vnotched configurations. In this technique, certain optimal point(s) on the notch flanks are obtained where the displacements are found to be highly accurate. Using the PSDT, the NSIFs are determined from the finite element (FE) displacements at these optimal point(s). The NSIFs of one pure mode I and two mixed mode (I/II) examples have been determined and excellent agreement of the present results with the published results is observed. The PSDT is efficient, robust and easy to be implemented in the available FE code.

In the present work a simple and efficient least squares method is implemented for accurate estimation of notch stress intensity factors (NSIFs) of sharp V-notches. Finite element (FE) stress components near a notch tip is used in the present method for determining the NSIFs. Pure mode I and mixed mode (I/II) examples are considered for numerical investigations. The mixed mode stress components are disintegrated into opening mode and shear mode stress components to separate out the mode I and mode II singularities. Thereafter, least squares method is implemented to calculate mixed mode NSIFs. The present method is easy to incorporate in existing standard finite element codes. The results obtained by the present method are found to be in good agreement with the published data.

The accuracy of measurement of opening mode stress intensity factor using strain gage techniques mainly depends on location of the strain gages. The present work proposes a finite element based simple procedure for accurate determination of three parameter zone and optimum strain gage location for various eccentric cracked configurations. In this paper, the effect of specimen size and crack length to width of the eccentric cracked plate on optimum location of strain gage is also studied. The results of the present investigation show that specimen size and ratio of crack length to width of the plate strongly influence the optimum location of strain gage.

A fully automatic advancing front type mesh generator to take care of crack problems has been presented. It is coupled with the Zienkiewicz and Zhu error estimator and the refinement methodology depends on the concept of strain energy concentration for completely automatic adaptive analysis of mixed-mode crack problems. For the first time energy based path independent M1-integral has been used to extract mixed-mode stress intensity factors in randomly changing quadratic triangular meshes. To fulfill the objective of automatic adaptive procedures, an approach has been suggested and validated for generation of integration paths automatically without user intervention. Stress intensity factors have been obtained within engineering accuracy.

A large number of thin films of cadmium oxide have been prepared on glass substrates by spray pyrolysis method. The prepared films have uniform thickness varying from 200–600 nm and good adherence to the glass substrate. A systematic study has been made on the influence of thickness on resistivity, sheet resistance, carrier concentration and mobility of the films. The resistivity, sheet resistance, carrier concentration and mobility values varied from 1·56–5·72×10−3 Ω-cm, 128–189 Ω/□, 1·6–3·9×1021 cm−3 and 0·3–3 cm2/Vs, respectively for varying film thicknesses. A systematic increase in mobility with grain size clearly indicates the reduction of overall scattering of charge carriers at the grain boundaries. The large concentration of charge carriers and low mobility values have been attributed to the presence of Cd as an impurity in CdO microcrystallites. Using the optical transmission data, the band gap was estimated and found to vary from 2·20–2·42 eV. These films have transmittance around 77% and average reflectance is below 2·6% in the spectral range 350–850 nm. The films aren-type and polycrystalline in nature. SEM micrographs of the CdO films were taken and the films exhibit clear grains and grain boundary formation at a substrate temperature as low as 523 K.