Fruit dehiscence in Brassicas

Dehiscence is a means by which some wild plants release their seeds. In Brassicas the mature fruit or 'pod', strictly a silique, releases seed by a sometimes explosive mechanism triggered by mechanical pressure and referred to as 'shatter'. This mechanism is a problem in Brassica crop plants and results in loss of seed, and hence loss of revenue, during harvesting. This problem is further compounded by the distribution of volunteers which contaminate future crops and the environment. The post-fertilisation development of the carpel wall of a number of Brassica species has been examined including, a range of Arabidopsis ecotypes and mutants, and fruits from two other Brassicas, Brassica napus and Brassica juncea, which exhibit differences in the dehiscence characteristic. These have been studied by a combination of cytological, cytochemical and molecular techniques. Following fertilisation, dehiscence zones form at the carpel margins, separating the carpel walls from the replum and forming two valves. Cells within the dehiscence zone exhibit reduced cellular cohesion due to breakdown of the middle lamella. Differentiation of the carpel wall layers results in a thickened exocarp, a senescing mesocarp, and modification of the endocarp layers in which the inner layer Enϸ lignifies whilst Enα collapses. It is proposed that the patterns of differentiation result in the development of the dehiscence mechanism. The dehiscence mechanism and pod 'shatter' is a result of; 1) weakening of valve attachment due to reduced cell cohesion in the dehiscence zone, and, 2) tensions which develop within the carpel walls due to desiccation and shrinkage of the mesocarp which is attached to a thickened, non-shrinking endocarp.The fruits from all of the Arabidopsis ecotypes examined exhibited a similar pattern of carpel wall development and similar dehiscence characteristics. Light microscopical examination of the fruits of Brassica napus and Brassica juncea which do not shatter as easily as those of Arabidopsis showed a different pattern of endocarp development in the post fertilised fruit. Enα tangential walls thickened considerably in the post-fertilised Brassica napus and Brassica juncea fruit, prior to the collapse of this cell layer. In Indian mustard, the Brassica juncea variety which had a non-shattering phenotype, the lignified walls of En6 were surrounded by a highly pectinised layer. This deposition of pectins confers more elasticity to the carpel walls, hence reducing the tensions which normally result in dehiscence and cause pod shatter. The model of the shattering and non-shattering phenotypes described in this study suggest a number of strategies which may be used to reduce the problems of pod shatter. These include modification of the separation layer to increase cellular cohesion, and modifications to the patterns of differentiation in the carpel wall to reduce the tensions which normally develop during fruit ripening

Development of the silique of Arabidopsis Thaliana

Using the silique of Arabidopsis as a model system, we are studying fruit development by a combination of cytological, cytochemical and molecular techniques. Within the floral bud the early gynoecium develops with differentiation of two major vascular bundles and two meristematic regions. The latter give rise to the ovules and combine to form the septum which separates the two loculi of the maturing fruit. Development of the carpel walls results in the differentiation of three specific layers, the endocarp, the mesocarp and the exocarp. After fertilisation absicission zones form between the carpel walls and the major vascular supplies to the developing ovules. The patterns of differentiation result in the dehiscence mechanism which disperses seeds from the shattering fruit. Such fruit shatter and seed dispersal mechanisms represent significant problems in a number of agricultural crops causing loss of seed yield and the distribution of volunteers. We have described the cytological events associated with the differentiation of the major tissue types associated with carpel and septal development, and identified a number of probes which act, by immunocytochemistry, in situ hybridisation or enzymecytochemistry, as appropriate markers for specific phases of differentiation. We have compared the development of the meristic clvl mutant, which shows anomalies in gynoecial development, with that of wild type, and are screening EMS-mutated stock for other variants of fruit development

CADASIL accelerated by acute hypotension: Arterial and venous contribution to leukoaraiosis

Objective: To underline the importance of blood pressure regulation in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) and to describe changes that occur in the veins in this condition, specifically venous collagenosis associated with leukoaraiosis. Methods: Case report with neuroimaging and pathologic data. Results: A 61-year-old man with genetically confirmed CADASIL was initially lucid following a motor vehicle accident but subsequently became hypotensive (60/40 mm Hg) due to an open femur fracture and required intubation. Multiple new white matter infarcts appeared on brain imaging. A second hypotensive episode days later was associated with new coin-sized infarcts in the bilateral corona radiata and cerebellar peduncles, and resulted in quadriplegia. No embolic source was found on cardiac or vascular imaging. He died 5 weeks post trauma. Autopsy revealed extensive subcortical and periventricular leukoencephalopathy and multiple cavitations involving deep subcortical gray and white matter. Small arteries had thickened walls, disruption of the muscularis, and intimal periodic acid-Schiff (PAS)-positive material. Both larger periventricular and small caliber veins had thickened walls that were PAS-negative and trichrome-positive, consistent with venous collagenosis. There was no pathologic evidence of global hypoxia or diffuse axonal injury. Conclusions: The findings suggest rapid acceleration of CADASIL pathology from acute hypotension in the setting of impaired vasoreactivity. In addition, collagenosis of veins in the affected white matter regions suggests that the veins may play an important, though largely overlooked, role in maintaining white matter integrity

Task force on immigration and higher education in Central Massachusetts

In August 2007, the Colleges of Worcester Consortium, Inc. created a task force to examine the issue of immigration and higher education in Central Massachusetts. It has become increasingly clear from recent demographic and economic studies and projections that the population in the northeast, and certainly in Central Massachusetts, is showing minimal growth. There is evidence that a decline in the “native-born” population is caused by significant out-migration due to a number of factors, including the high cost of living, limited career opportunities and a declining birth rate. The limited population growth that is evident is due primarily to the recent influx of immigrants to this area, with the most significant numbers in Worcester coming from Ghana, Brazil, the Dominican Republic, Kenya, El Salvador, Albania and Liberia. It is also clear that the area’s economy is becoming more knowledge-based with an increasing percentage of all new jobs requiring some form of postsecondary education. According to the 2007 Massachusetts Department of Workforce Development’s Job Vacancy Survey, 38 percent of current job vacancies in Massachusetts require an associate’s degree or higher. This represents an increase from 30 percent in 2003. Consequently, the level of education that the immigrant population attains is of vital importance to everyone—not only to immigrant students and their families but also to the economic well-being of the entire region. The Task Force was charged with researching the barriers to higher education faced by this new wave of immigrants and suggesting recommendations to address those barriers. The 36-member Task Force was made up of representatives from Consortium member institutions; federal, state and local governments; community and faithbased organizations; the Worcester Public Schools; the Massachusetts Board of Higher Education; and the Massachusetts Immigrant and Refugee Advocacy (MIRA) Coalition. Meetings were held over six months, during which the Task Force identified three main barriers faced by immigrant communities in accessing higher education, and sub-committees were created to work on each of these. Speakers were invited to present on topics of interest. Two public hearings were held, the first of which was conducted at Worcester State College in October. It attracted community representatives, as well as college and high school faculty and administrators. The second hearing, held at the downtown branch of Quinsigamond Community College (QCC) in December, was attended by immigrants (English for Speakers of Other Languages – ESOL and GED) students as well as QCC staff.Published versio

Secular trends in reported portion size of food and beverages consumed by Irish adults

The present analysis aimed to investigate the changes in the reported portion sizes (PS) of foods and beverages commonly consumed by Irish adults (18–64 years) from the North South Ireland Food Consumption Survey (NSIFCS) (1997–2001) and the National Adult Nutrition Survey (NANS) (2008–10). Food PS, which are defined as the weight of food (g) consumed per eating occasion, were calculated for comparable foods and beverages in two nationally representative cross-sectional Irish food consumption surveys and were published in NSIFCS and NANS. Repeated measure mixed model analysis compared reported food PS at the total population level as well as subdivided by sex, age, BMI and social class. A total of thirteen commonly consumed foods were examined. The analysis demonstrated that PS significantly increased for five foods (‘white sliced bread’, ‘brown/wholemeal breads’, ‘all meat, cooked’, ‘poultry, roasted’ and ‘milk’), significantly decreased for three (‘potatoes’, ‘chips/wedges’ and ‘ham, sliced’) and did not significantly change for five foods (‘processed potato products’, ‘bacon/ham’, ‘cheese’, ‘yogurt’ and ‘butter/spreads’) between the NSIFCS and the NANS. The present study demonstrates that there was considerable variation in the trends in reported food PS over this period

The state of the Martian climate

60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes

FGF4 and Retinoic Acid Direct Differentiation of hESCs into PDX1-Expressing Foregut Endoderm in a Time- and Concentration-Dependent Manner

BACKGROUND: Retinoic acid (RA) and fibroblast growth factor 4 (FGF4) signaling control endoderm patterning and pancreas induction/expansion. Based on these findings, RA and FGFs, excluding FGF4, have frequently been used in differentiation protocols to direct differentiation of hESCs into endodermal and pancreatic cell types. In vivo, these signaling pathways act in a temporal and concentration-dependent manner. However, in vitro, the underlying basis for the time of addition of growth and differentiation factors (GDFs), including RA and FGFs, as well as the concentration is lacking. Thus, in order to develop robust and reliable differentiation protocols of ESCs into mature pancreatic cell types, including insulin-producing beta cells, it will be important to mechanistically understand each specification step. This includes differentiation of mesendoderm/definitive endoderm into foregut endoderm--the origin of pancreatic endoderm. METHODOLOGY/PRINCIPAL FINDINGS: Here, we provide data on the individual and combinatorial role of RA and FGF4 in directing differentiation of ActivinA (AA)-induced hESCs into PDX1-expressing cells. FGF4's ability to affect endoderm patterning and specification in vitro has so far not been tested. By testing out the optimal concentration and timing of addition of FGF4 and RA, we present a robust differentiation protocol that on average generates 32% PDX1(+) cells. Furthermore, we show that RA is required for converting AA-induced hESCs into PDX1(+) cells, and that part of the underlying mechanism involves FGF receptor signaling. Finally, further characterization of the PDX1(+) cells suggests that they represent foregut endoderm not yet committed to pancreatic, posterior stomach, or duodenal endoderm. CONCLUSION/SIGNIFICANCE: In conclusion, we show that RA and FGF4 jointly direct differentiation of PDX1(+) foregut endoderm in a robust and efficient manner. RA signaling mediated by the early induction of RARbeta through AA/Wnt3a is required for PDX1 expression. Part of RA's activity is mediated by FGF signaling

Glucose transporter 1 expression as a marker of prognosis in oesophageal adenocarcinoma.

BACKGROUND: The current TNM staging system for oesophageal adenocarcinoma (OAC) has limited ability to stratify patients and inform clinical management following neo-adjuvant chemotherapy and surgery. RESULTS: Functional genomic analysis of the gene expression data using Gene Set Enrichment Analysis (GSEA) identified GLUT1 as putative prognostic marker in OAC.In the discovery cohort GLUT1 positivity was observed in 114 patients (80.9%) and was associated with poor overall survival (HR 2.08, 95% CI 1.1-3.94; p=0.024) following multivariate analysis. A prognostic model incorporating GLUT1, CRM and nodal status stratified patients into good, intermediate and poor prognosis groups (p< 0.001) with a median overall survival of 16.6 months in the poorest group.In the validation set 182 patients (69.5%) were GLUT1 positive and the prognostic model separated patients treated with neo-adjuvant chemotherapy and surgery (p<0.001) and surgery alone (p<0.001) into three prognostic groups. PATIENTS AND METHODS: Transcriptional profiling of 60 formalin fixed paraffin-embedded (FFPE) biopsies was performed. GLUT1 immunohistochemical staining was assessed in a discovery cohort of 141 FFPE OAC samples treated with neo-adjuvant chemotherapy and surgery at the Northern Ireland Cancer Centre from 2004-2012. Validation was performed in 262 oesophageal adenocarcinomas collected at four OCCAMS consortium centres. The relationship between GLUT1 staining, T stage, N stage, lymphovascular invasion and circumferential resection margin (CRM) status was assessed and a prognostic model developed using Cox Proportional Hazards. CONCLUSIONS: GLUT1 staining combined with CRM and nodal status identifies a poor prognosis sub-group of OAC patients and is a novel prognostic marker following potentially curative surgical resection