Nonlinear ptychographic coherent diffractive imaging

Ptychographic Coherent diffractive imaging (PCDI) is a significant advance in imaging allowing the measurement of the full electric field at a sample without use of any imaging optics. So far it has been confined solely to imaging of linear optical responses. In this paper we show that because of the coherence-preserving nature of nonlinear optical interactions, PCDI can be generalised to nonlinear optical imaging. We demonstrate second harmonic generation PCDI, directly revealing phase information about the nonlinear coefficients, and showing the general applicability of PCDI to nonlinear interactions

The Effect of Biased Ligand Signaling on Cardiomyocyte Proliferation

Myocardial infarction (MI) (i.e. heart attack) is the permanent death (necrosis) of heart muscle resulting from prolonged lack of oxygen supply (ischemia) (NHLBI, 2015). Without immediate restoration of blood flow, death of heart muscle will ensue (NHLBI, 2015). Every year, more than one million Americans experience MI, and approximately half of them die (Medline Plus, 2015). Though successful return to normal activities post-infarction is highly possible, individuals are nevertheless at risk for complications due to ischemic cardiac tissue (Brown, 2015). The mammalian heart has poor regenerative capabilities – cardiomyocytes cannot proliferate; therefore, cardiac muscle does not repair itself. Recently, the notion that adult cardiomyocytes are unable to proliferate has been challenged (Bergmann, 2009). However, despite intensive research efforts, the mechanisms governing cardiomyocyte cell cycle reentry and proliferation remain unknown. The Dzau lab has recently identified a novel paracrine protein synthesized by mesenchymal stem cells, C3orf58, which they have termed hypoxia and Akt induced stem cell factor (HASF) (Beigi, 2013). Preliminary data has indicated that it harbors the capacity to promote neonatal and adult cardiomyocyte proliferation, and thereby, cardiac regeneration (Beigi, 2013). Previously, I hypothesized that HASF promoted cardiomyocyte proliferation via the CAK complex/ERK signaling pathway (Baksh, 2016). However, I observed that it was IGF-1, not HASF, that promoted cardiomyocyte proliferation via the CAK complex/AKT signaling pathway (Baksh, 2016). Therefore, the goal of this study was to delineate the molecular pathway by which IGF1-AKT-activated CAK complex promotes cardiomyocyte proliferation. IGF1-activated CDKs and cyclins were identified by incubating cells with IGF-1 for 12hr and performing Western blot analysis, probing with cyclin E1 and pCDK2 antibodies. Additionally, the AKT signaling pathway was inhibited by triciribine to assess to effect of AKT inhibition on CDK2 phosphorylation and cyclin E1 expression. IGF-1 was observed to enhance CDK2 phosphorylation via AKT stimulation and CAK activation. This finding will serve to enhance our understanding of the mechanisms underlying cardiomyocyte cell cycle reentry, and will thus make IGF-1 a potential therapeutic candidate for myocardial repair post-infarction

Emergency management of stroke in the era of mechanical thrombectomy

Emergency management of stroke has been directed at the delivery of recombinant tissue plasminogen activator (tPA) in a timely fashion. Because of the many limitations attached to the delivery of tPA and the perceived benefits accrued to tPA, its use has been limited. Mechanical thrombectomy, a far superior therapy for the largest and most disabling strokes, large vessel occlusions (LVOs), has changed the way acute strokes are managed. Aside from the rush to deliver tPA, there is now a need to identify LVO and refer those patients with LVO to physicians and facilities capable of delivering urgent thrombectomy. Other parts of emergency department management of stroke are directed at identifying and mitigating risk factors for future strokes and at preventing further damage from occurring. We review here the most recent literature supporting these advances in stroke care and present a framework for understanding the role that emergency physicians play in acute stroke care

PATTERN OF FARMING PRACTICES AND SUSTAINABLE AGRICULTURAL DEVELOPMENT: A STUDY ON THE LINKAGE

Agricultural development is the sine qua non for socio-economic development of a nation in general and developing countries in particular. The sustainable agriculture can be traced that it enhances the environmental quality and the resource base upon which agriculture depends. This form of agriculture is expected to provide basic human food and other major needs which are socially desirable and economically viable. This awareness has come to the centre stage of global debate as a result of degradation of natural resources and environment. The present study is an attempt to examine the farming practices in Cuddalore district of Tamil Nadu, India. The study is an empirical investigation based upon the data collected from the above mentioned field. The data were collected from 335 respondents of the district who were selected through multi-stage stratified random sampling method. In the first phase one developed taluk, a backward taluk, and a most backward taluk were identified. In the second phase one community development block is selected from each taluk. Third phase is the selection of five villages from each block. And at the final stage from each village 10 per cent of the farm households were selected at random. From the selected respondents the data were collected by using the tool of interview-schedule. The farming pattern of each educational group is associated with the views on advantages of cultivating traditional crop variety and the awareness of impact of chemical fertilizer on land and crops

PATTERN OF FARMING PRACTICES AND SUSTAINABLE AGRICULTURAL DEVELOPMENT: A STUDY ON THE LINKAGE

Agricultural development is the sine qua non for socio-economic development of a nation in general and developing countries in particular. The sustainable agriculture can be traced that it enhances the environmental quality and the resource base upon which agriculture depends. This form of agriculture is expected to provide basic human food and other major needs which are socially desirable and economically viable. This awareness has come to the centre stage of global debate as a result of degradation of natural resources and environment. The present study is an attempt to examine the farming practices in Cuddalore district of Tamil Nadu, India. The study is an empirical investigation based upon the data collected from the above mentioned field. The data were collected from 335 respondents of the district who were selected through multi-stage stratified random sampling method. In the first phase one developed taluk, a backward taluk, and a most backward taluk were identified. In the second phase one community development block is selected from each taluk. Third phase is the selection of five villages from each block. And at the final stage from each village 10 per cent of the farm households were selected at random. From the selected respondents the data were collected by using the tool of interview-schedule. The farming pattern of each educational group is associated with the views on advantages of cultivating traditional crop variety and the awareness of impact of chemical fertilizer on land and crops

Human palatine tonsil: a new potential tissue source of multipotent mesenchymal progenitor cells

INTRODUCTION: Mesenchymal progenitor cells (MPCs) are multipotent progenitor cells in adult tissues, for example, bone marrow (BM). Current challenges of clinical application of BM-derived MPCs include donor site morbidity and pain as well as low cell yields associated with an age-related decrease in cell number and differentiation potential, underscoring the need to identify alternative sources of MPCs. Recently, MPC sources have diversified; examples include adipose, placenta, umbilicus, trabecular bone, cartilage, and synovial tissue. In the present work, we report the presence of MPCs in human tonsillar tissue. ----- METHODS: We performed comparative and quantitative analyses of BM-MPCs with a subpopulation of adherent cells isolated from this lymphoid tissue, termed tonsil-derived MPCs (T-MPCs). The expression of surface markers was assessed by fluorescent-activated cell sorting analysis. Differentiation potential of T-MPCs was analyzed histochemically and by reverse transcription-polymerase chain reaction for the expression of lineage-related marker genes. The immunosuppressive properties of MPCs were determined in vitro in mixed lymphocyte reactions. ----- RESULTS: Surface epitope analysis revealed that T-MPCs were negative for CD14, CD31, CD34, and CD45 expression and positive for CD29, CD44, CD90, and CD105 expression, a characteristic phenotype of BM-MPCs. Similar to BM-MPCs, T-MPCs could be induced to undergo adipogenic differentiation and, to a lesser extent, osteogenic and chondrogenic differentiation. T-MPCs did not express class II major histocompatibility (MHC) antigens, and in a similar but less pronounced manner compared with BM-MPCs, T-MPCs were immunosuppressive, inhibiting the proliferation of T cells stimulated by allogeneic T cells or by non-specific mitogenic stimuli via an indoleamine 2,3-dioxygenase-dependent mechanism. ----- CONCLUSION: Human palatine T-MPCs represent a new source of progenitor cells, potentially applicable for cell-based therapies

Exploring semantic verbal fluency patterns and their relationship to age and Alzheimer's disease in adults with Down syndrome

Introduction: Adults with Down syndrome (DS) are at ultra-high risk of developing Alzheimer's disease (AD), characterized by poor episodic memory and semantic fluency in the preclinical phase in the general population. We explored semantic fluency performance in DS and its relationship to age, AD, and blood biomarkers. Methods: A total of 302 adults with DS at baseline and 87 at follow-up from the London Down Syndrome Consortium cohort completed neuropsychological assessments. Blood biomarkers were measured with the single molecule array technique in a subset of 94 participants. Results: Poorer verbal fluency performance was observed as age increases. Number of correct words declined in those with AD compared to those without over 2 years and was negatively correlated with neurofilament light (r = –0.37, P =.001) and glial fibrillary acidic protein (r = –0.31, P =.012). Discussion: Semantic fluency may be useful as an early indicator of cognitive decline and provide additional information on AD-related change, showing associations with biomarkers in DS

Differential Associations of Apolipoprotein E ε4 Genotype With Attentional Abilities Across the Life Span of Individuals With Down Syndrome

Importance: Risk of Alzheimer disease (AD) is particularly high for individuals with Down syndrome (DS). The ε4 allele of the apolipoprotein E gene (APOE ε4) is associated with an additional risk for AD. In typical development, there is evidence that the APOE ε4 genotype is associated with an early cognitive advantage. Here we investigate associations of APOE ε4 with attention across the life span of individuals with DS. Objective: To investigate associations between APOE ε4 and attentional abilities in young children and in adults with DS. Design, Settings, and Participants: In this cross-sectional study, data were collected from 80 young children with DS (8-62 months of age) and 240 adults with DS (16-71 years of age) during the period from 2013 to 2018 at a research center to examine the association between APOE status (ε4 carrier vs ε4 noncarrier) and attentional abilities. Exposure: APOE status (ε4 carrier vs ε4 noncarrier). Main Outcomes and Measures: For the children, attentional ability was assessed using an eye-tracking paradigm, the gap-overlap task; the size of the gap effect was the primary outcome. For the adults, attentional ability was assessed using the CANTAB simple reaction time task; the standard deviation of response time latencies was the primary outcome. Cross-sectional developmental trajectories were constructed linking attentional ability with age in ε4 carriers and ε4 noncarriers for children and adults separately. Results: The child sample comprised 23 ε4 carriers and 57 ε4 noncarriers. The adult sample comprised 61 ε4 carriers and 179 ε4 noncarriers. For the children, a significant difference between trajectory intercepts (ηp2 = 0.14) indicated that ε4 carriers (B = 100.24 [95% CI, 18.52-181.96]) exhibited an attentional advantage over ε4 noncarriers (B = 314.78 [95% CI, 252.17-377.39]). There was an interaction between APOE status and age (ηp2 = 0.10); while the gap effect decreased with age for ε4 noncarriers (B = -4.58 [95% CI, -6.67 to -2.48]), reflecting the development of the attention system, there was no change across age in ε4 carriers (B = 0.77 [95% CI, -1.57 to 3.12]). For the adults, there was no main effect of ε4 carrier status, but there was an interaction between APOE status and age (B = 0.02 [95% CI, 0.004-0.07]), so that ε4 carriers had poorer attentional ability than ε4 noncarriers at older ages. Conclusions and Relevance: APOE ε4 is associated with an attentional advantage early in development and a disadvantage later in life for individuals with DS, similar to the pattern reported in typical development. Understanding the differential role of APOE across the life span is an important step toward future interventions