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Host-environment mismatches associated with subalpine fir decline in Colorado

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Journal of Forestry Research 2016年第5期27卷 1177-1189页

作者： Robin m. Reich john E. Lundquist Kristina Hughes Colorado State University Fort Collins CO USA U.S. Forest Service Anchorage Anchorage AK 99501 USA

Subalpine fir decline （SFD） has killed more trees in Colorado＇s high elevation forests than any other insect or disease problem. The widespread nature of this disorder suggests that the cause involves climatic factors. We examined the influence of varying combinations of average annual temperature and precipitation on the incidence and distribution of SFD. Climatic transition matrices generated in this study indicate that most healthy trees are found in climatic zones with moderate to low temperatures and high precipitation; whereas, SFD occurs mostly in zones of moderate temperatures and moderate precipitation. The contrasting distributions define an environmental mismatch. Forests matched with favorable climatic conditions thrive; those that are mismatched can become vulnerable to decline disease.

关键词： Abiotic disorder Climate stress High elevation forests Forest disease - Subalpine fir

Central role of the LEAFY COTYLEDON1 transcription factor in seed development

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Journal of Integrative Plant Biology 2019年第5期61卷 564-580页

作者： Leonardo Jo Julie m.Pelletier john J.Harada Department of Plant Biology and Plant Biology Graduate Group University of CaliforniaDavis USA

Seed development is a complex period of the flowering plant life *** fertilization,the three main regions of the seed,embryo,endosperm and seed coat,undergo a series of developmental processes that result in the production of a mature seed that is developmentally arrested,desiccated,and metabolically *** processes are highly coordinated,both temporally and spatially,to ensure the proper growth and development of the *** transcription factor,LEAFY COTYLEDON1(LEC1),is a central regulator that controls several aspects of embryo and endosperm development,including embryo morphogenesis,photosynthesis,and storage reserve ***,LEC1 regulates distinct sets of genes at different stages of seed *** its critical importance for seed development,an understanding of the mechanisms underlying LECi's multifunctionality is only beginning to be *** studies describe the roles of specific transcription factors and the hormones,gibberellic acid and abscisic acid,in controlling the activity and transcriptional specificity of LEC1 across seed ***,studies indicate that LEC1 acts as a pioneer transcript!on factor to promote epigenetic reprogramming during *** this review,we discuss the mechanisms that enable LEC1 to serve as a central regulator of seed development.

关键词： Seed development flowering plant seed development

Exercise-dependent regulation of glial cell line-derived neurotrophic factor （GDNF） expression in skeletal muscle and its importance for the neuromuscular system

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Frontiers in Biology 2013年第1期8卷 101-108页

作者： john-mary VIANNEY monica J. mCCULLOUGH Amy m. GYORKOS, john m. SPITSBERGEN Department of Biological Scienees Western Michigan University Kalamazoo MI 49098-5410 USA

The focus of this review is to highlight the importance of glial cell line-derived neurotrophic factor （GDNF） for the motor nervous system. GDNF is the most potent survival factor for motor neurons, where it enhances maintenance and survival of both developing and mature motor neurons in vivo and in vitro. GDNF aids in neuromuscular junction formation, maintenance, and plasticity, where skeletal muscle-derived GDNF may be responsible for this phenomenon. Increased levels of physical activity can increase GDNF protein levels in skeletal muscle, where alterations in acetylcholine and acetylcholine receptor activation may be involved in regulation of these changes observed. With inactivity and disuse, GDNF expression shows different patterns of regulation in the central and peripheral nervous systems. Due to its potent effects for motor neurons, GDNF is being extensively studied in neuromuscular diseases.

关键词： glial cell line-derived neurotrophic factor neuromuscular junction motor neurons skeletal muscle

Lipolysis supports bone formation by providing osteoblasts with endogenous fatty acid substrates to maintain bioenergetic status

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Bone Research 2023年第4期11卷 876-894页

作者： Ananya Nandy Ron C.m.Helderman Santosh Thapa Shobana Jayapalan Alison Richards Nikita Narayani michael P.Czech Clifford J.rosen Elizabeth Rendina-Ruedy Department of medicine Division of Clinical PharmacologyVanderbilt University Medical CenterNashvilleTN 37232USA Program in molecular medicine University of Massachusetts Chan Medical SchoolWorcesterMA 01605USA maine medical Center Research Institute ScarboroughMEUSA molecular Physiology and Biophysics Vanderbilt UniversityNashvilleTN 37232USA

Bone formation is a highly energy-demanding process that can be impacted by metabolic *** has been considered the principal substrate for osteoblasts,although fatty acids are also important for osteoblast ***,we report that osteoblasts can derive energy from endogenous fatty acids stored in lipid droplets via lipolysis and that this process is critical for bone *** such,we demonstrate that osteoblasts accumulate lipid droplets that are highly dynamic and provide the molecular mechanism by which they serve as a fuel source for energy generation during osteoblast *** cytoplasmic lipolysis leads to both an increase in lipid droplet size in osteoblasts and an impairment in osteoblast *** fatty acids released by lipolysis from these lipid droplets become critical for cellular energy production as cellular energetics shifts towards oxidative phosphorylation during nutrient-depleted *** vivo,conditional deletion of the ATGL-encoding gene Pnpla2 in osteoblast progenitor cells reduces cortical and trabecular bone parameters and alters skeletal lipid ***,our data demonstrate that osteoblasts store fatty acids in the form of lipid droplets,which are released via lipolysis to support cellular bioenergetic status when nutrients are *** in this process result in impairment of bone formation,specifically reducing ATP production and overall osteoblast function.

关键词： endogenous maintain osteoblast

Reconstructing seafloor age distributions in lost ocean basins

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Geoscience Frontiers 2021年第2期12卷 769-780页

作者： Simon Williams Nicky m.Wright john Cannon Nicolas Flament R.Dietmar müller Department of Geology Northwest UniversityXi’an710069China State Key Laboratory of Continental Dynamics Northwest UniversityXi’an710069China Research School of Earth Sciences The Australian National UniversityACT2601Australia ARC Centre of Excellence for Climate Extremes The Australian National UniversityACT2601Australia EarthByte Group School of GeosciencesUniversity of SydneyAustralia GeoQuEST Research Centre School of EarthAtmospheric and Life SciencesUniversity of WollongongNorthfields AvenueNSW2522Australia

Reconstructions of past seafloor age make it possible to quantify how plate tectonic forces,surface heat flow,ocean basin volume and global sea level have varied through geological ***,past ocean basins that have now been subducted cannot be uniquely reconstructed,and a significant challenge is how to explore a wide range of possible ***,we investigate possible distributions of seafloor ages from the late Paleozoic to present using published full-plate reconstructions and a new,efficient seafloor age reconstruction workflow,all developed using the open-source software *** test alternative reconstruction models and examine the influence of assumed spreading rates within the Panthalassa Ocean on the reconstructed history of mean seafloor age,oceanic heat flow,and the contribution of ocean basin volume to global sea *** reconstructions suggest variations in mean seafloor age of~15 myr during the late Paleozoic,similar to the amplitude of variations previously proposed for the Cretaceous to *** reconstructed oceanic age-area distributions are broadly compatible with a scenario in which the long-period fluctuations in global sea level since the late Paleozoic are largely driven by changes in mean seafloor *** suggestions of a constant rate of seafloor production through time can be modelled using our workflow,but require that oceanic plates in the Paleozoic move slower than continents based on current reconstructions of continental motion,which is difficult to reconcile with geodynamic studies.

关键词： Plate reconstructions Sea level Seafloor spreading

Campaign-style U-Pb titanite petrochronology:Along-strike variations in timing of metamorphism in the Himalayan metamorphic core

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Geoscience Frontiers 2019年第3期10卷 827-847页

作者： Catherine m.mottram john m.Cottle Andrew R.C.Kylander-Clark School of Earth and Environmental Sciences University of Portsmouth Department of Earth Science University of CaliforniaSanta Barbara

Present-day along-strike heterogeneities within the Himalayan orogen are seen at many scales, from variations within the deep architecture of the lithospheric mantle, to differences in geomorphologic surface processes. Here, we present an internally consistent petrochronologic dataset from the Himalayan metamorphic core(HmC), in order to document and investigate the causes of along-strike variations in its Oligocene-miocene tectonic history. Laser ablation split-stream analysis was used to date and characterise the geochemistry of titanite from 47 calc-silicate rocks across >2000 km along the *** combined U-Pb-REE-Zr single mineral dataset circumvents uncertainties associated with interpretations based on data compilations from different studies, mineral systems and laboratories, and allows for direct along-strike comparisons in the timing of metamorphic processes. Titanite dates range from ～30 ma to 12 ma, recording(re-)crystallization between 625 ℃ and 815 ℃. Titanite T-t data overlap with previously published P-T-t paths from interleaved peltic rocks, demonstrating the usefulness of titanite petrochronology for recording the metamorphic history in lithologies not traditionally used for thermobarometry. Overall, the data indicate a broad eastward-younging trend along the *** in the duration and timing of metamorphism within the HmC are best explained by alongstrike variations in the position of ramps on the basal detachment controlling a two-stage process of preferential ductile accretion at depth followed by the formation of later upper-crust brittle *** processes, coupled with variable erosion, resulted in the asymmetric exhumation of a younger,thicker crystalline core in the eastern Himalaya.

关键词： Himalaya Petrochronology Titanite metamorphic petrology

Intermediate hyperglycemia in early pregnancy:A South Asian perspective

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World Journal of Diabetes 2023年第5期14卷 573-584页

作者： john Punnose Komal Sukhija Rashika m Rijhwani Department of Endocrinology and metabolism St.Stephen’s HospitalDelhi 110054India Department of Endocrinology St.Stephen’s HospitalDelhi 110054India

“Intermediate hyperglycemia in early pregnancy(IHEP)”refers to mild hyperglycemia detected before 24 gestational weeks(GW),satisfying the criteria for the diagnosis of gestational diabetes *** professional bodies recommend routine screening for“overt diabetes”in early pregnancy,which identifies a significant number of women with mild hyperglycemia of undetermined significance.A literature search revealed that one-third of GDm women in South Asian countries are diagnosed before the conventional screening period of 24 GW to 28 GW;hence,they belong in the IHEP *** hospitals in this region diagnose IHEP by oral glucose tolerance test(OGTT)using the same criteria used for GDm diagnosis after 24 *** is some evidence to suggest that South Asian women with IHEP are more prone to adverse pregnancy events than women with a diagnosis of GDm after 24 GW,but this observation needs to be proven by randomized control *** plasma glucose is a reliable screening test for GDm that can obviate the need for OGTT for GDm diagnosis among 50%of South Asian pregnant ***1c in the first trimester predicts GDm in later pregnancy,but it is not a reliable test for IHEP *** is evidence to suggest that HbA1c in the first trimester is an independent risk factor for several adverse pregnancy *** research to identify the pathogenetic mechanisms behind the fetal and maternal effects of IHEP is strongly recommended.

关键词： Intermediate hyperglycemia Early pregnancy Gestational diabetes South Asian women Adverse events Asian Indian

The 12th International Symposium on Spermatology

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Asian Journal of Andrology 2015年第4期17卷 519-520页

作者： R john Aitken Jim m Cummins Brett Nixon Priority Research Centre in Reproductive Science Discipline of Biological Sciences and HunterMedical Research Institute University of NewcastleNSW 2308 Australia Division of Veterinary andBiomedical Sciences Murdoch University MurdochWA. Australia.

The 12th International Symposium of Spermatology continued the excellent tradition of this meeting since its inception in 1969 when the first Symposium was held in Italy under the Chairmanship of Professor Baccio Baccetti. This unique Symposium is held every 4 years and serves as a beacon for sperm cell biologists from all over the world, regardless of which species, animal or plant, they are working on. This willingness to embrace the fundamental biology of this distinctive cell type without species limitations is one of the hallmarks of this Symposium. For sperm biologists - it is our Olympics. The meeting in Newcastle, NSW brought together around 300 biologists from more than 22 different countries covering North and South America, Africa, Europe, Asia and Australia. Given the considerable distances and high cost involved in travelling to the East Coast of NSW, this was an outstanding outcome. The Symposium featured a series of 31 plenary lectures culminating in the prestigious Thaddeus mann memorial Lecture, which was delivered with typical grace and brilliance by Professor masaru Okabe.

关键词： International Symposium Spermatology

Genetic variability of the stable fly assessed on a global scale using amplified fragment length polymorphism

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Insect Science 2016年第5期23卷 695-703页

作者： Kathleen m Kneeland Steven R. Skoda john E. Foster Department of Entomology 103 Entomology Haft University of Nebraska-Lincoln Lincoln NE 68583 USDA-ARS-KBUSLIRL Screwworm Research Unit 2700 Fredericksburg Road Kern/ille TX 78028 USA

The stable fly, Stomoxys calcitrans （L.）（Diptera： muscidae）, is a blood-feeding, economically important pest of animals and humans worldwide. Improved management strategies are essential and their development would benefit from studies on genetic di- versity of stable flies. Especially if done on a global scale, such research could generate information necessary for the development and application of more efficient control meth- ods. Herein we report on a genetic study of stable flies using amplified fragment length polymorphism, with samples of 10-40 individuals acquired from a total of 25 locations in the Nearctic, Neotropic, Palearctic, Afrotropic and Australasian biogeographical regions. We hypothesized that genetic differentiation would exist across geographical barriers. Although Fsx （0.33） was moderately high, the Gsx （0.05; representing genetic diversity between individuals） was very low; Nm values （representing gene flow） were high （9.36）. The mismatch distribution and tests of neutrality suggested population expansion, with no genetic differentiation between locations. The analysis of molecular variance （AmOVA） results showed the majority of genetic diversity was within groups. The mantel test showed no correlation between geographic and genetic distance; this strongly supports the AmOVA results. These results suggest that stable flies did not show genetic differentiation but are panmictic, with no evidence of isolation by distance or across geographical barriers.

关键词： AFLP biting flies external parasites genetic diversity livestock pests Stomoxys calcitrans