222 research outputs found
Poor survival outcomes in HER2 positive breast cancer patients with low grade, node negative tumours
We present a retrospective analysis on a cohort of low-grade, node-negative patients showing that human epidermal growth factor receptor 2 (HER2) status significantly affects the survival in this otherwise very good prognostic group. Our results provide support for the use of adjuvant trastuzumab in patients who are typically classified as having very good prognosis, not routinely offered standard chemotherapy, and who as such do not fit current UK prescribing guidelines for trastuzumab
Excretion patterns of coccidian oocysts and nematode eggs during the reproductive season in Northern Bald Ibis (Geronticus eremita)
Individual reproductive success largely depends on the ability to optimize behaviour, immune function and the physiological stress response. We have investigated correlations between behaviour, faecal steroid metabolites, immune parameters, parasite excretion patterns and reproductive output in a critically endangered avian species, the Northern Bald Ibis (Geronticus eremita). In particular, we related haematocrit, heterophil/lymphocyte ratio, excreted immune-reactive corticosterone metabolites and social behaviour with parasite excretion and two individual fitness parameters, namely, number of eggs laid and number of fledglings. We found that the frequency of excretion of parasites’ oocysts and eggs tended to increase with ambient temperature. Paired individuals excreted significantly more samples containing nematode eggs than unpaired ones. The excretion of nematode eggs was also significantly more frequent in females than in males. Individuals with a high proportion of droppings containing coccidian oocysts were more often preened by their partners than individuals with lower excretion rates. We observed that the more eggs an individual incubated and the fewer offspring fledged, the higher the rates of excreted samples containing coccidian oocysts. Our results confirm that social behaviour, physiology and parasite burden are linked in a complex and context-dependent manner. They also contribute background information supporting future conservation programmes dealing with this critically endangered species
Characterization of the ELM-free Negative Triangularity Edge on DIII-D
Tokamak plasmas with strong negative triangularity (NT) shaping typically
exhibit fundamentally different edge behavior than conventional L-mode or
H-mode plasmas. Over the entire DIII-D database, plasmas with sufficiently
negative triangularity are found to be inherently free of edge localized modes
(ELMs), even at injected powers well above the predicted L-H power threshold. A
critical triangularly (), consistent with
inherently ELM-free operation is identified, beyond which access to the second
stability region for infinite- ballooning modes closes on DIII-D. It is also
possible to close access to this region, and thereby prevent an H-mode
transition, at weaker average triangularities
() provided that at least one of the two
x-points is still sufficiently negative. Enhanced low field side magnetic
fluctuations during ELM-free operation are consistent with additional
turbulence limiting the NT edge gradient. Despite the reduced upper limit on
the pressure gradient imposed by ballooning stability, NT plasmas are able to
support small pedestals and are typically characterized by an enhancement of
edge pressure gradients beyond those found in traditional L-mode plasmas.
Further, the pressure gradient inside of this small pedestal is unusually
steep, allowing access to high core performance that is competitive with other
ELM-free regimes previously achieved on DIII-D. Since ELM-free operation in NT
is linked directly to the magnetic geometry, NT fusion pilot plants are
predicted to maintain advantageous edge conditions even in burning plasma
regimes, potentially eliminating reactor core-integration issues caused by
ELMs
Pronounced turnover of vascular plant species in Central European arable fields over 90 years
We studied changes in vascular plant species occurring in Central European (Germany, Czech Republic, Slovakia, Switzerland, Liechtenstein, Austria, Hungary, Northern Italy, Slovenia and Croatia) arable fields and their edges from 1930 to 2019. To correct for bias in the data, we used occupancy modeling to analyze changes in the occupancy, i.e., distribution ranges sizes, of the 359 most common species in the AgriWeedClim database. We used ecological indicator values, native versus alien (archaeophyte, neophyte) status, and species affinity to arable habitats to assess changes in the occupancy of species with different environmental preferences and biogeographic origins. We found only a small decline in overall species occupancy over time, with a median occupancy change of −0.1 %, possibly due to the exclusion of rare species from modeling. Species turnover was more pronounced, with 72 species decreasing to less than half of their initial occupancy and 77 species more than doubling their initial occupancy. Species with environmental preferences for nutrient-rich sites with neutral pH increased in occupancy whereas species typical for arable fields decreased. No response to climate change (i.e., increased occupancy of thermophilous or drought-tolerant species) was detected. Archaeophytes and native species decreased whereas neophytes increased in occupancy. Taken together, results suggest that the biodiversity of arable fields is changing largely in response to anthropogenic habitat changes
Random amplified polymorphic DNA (RAPD) analysis of Mycobacterium tuberculosis strains in India
The usefulness of random amplification of polymorphic DNA (RAPD) analysis for typing Indian strains of M. tuberculosis was investigated. M. tuberculosis H37Rv, M. tuberculosis DT and 42 clinical isolates of M. tuberculosis were subjected to RAPD-PCR using 7 random decamer primers. All 7 primers were found to be differentiated and produced specific RAPD profiles. The polymorphic amplicons served as RAPD markers for M. tuberculosis. The dendrograms, obtained by different primers, showed the discriminatory ability of the primers. RAPD analysis provided a rapid and easy means of identifying polymorphism in M. tuberculosis isolates, and it was found to be a valuable alternative epidemiological tool. In addition, the results of the present study showed heterogeneity in the M. tuberculosis strains in the population studied
Drift kinetic theory of the NTM magnetic islands in a finite beta general geometry tokamak plasma
In (Imada et al 2019 Nucl. Fusion 59 046016 and references therein) a new 4D drift kinetic nonlinear theory, valid in the limit of a low beta, small inverse aspect ratio, circular cross section, toroidal geometry, to describe the plasma response to the neoclassical tearing mode (NTM) magnetic perturbation is derived. In (Dudkovskaia et al 2021 Plasma Phys. Control. Fusion 63 054001) this theory is reduced in a low collisionality limit, which allows a dimensionality reduction to a 3D problem to efficiently resolve the collisional dissipation layer in the vicinity of the trapped-passing boundary. (Dudkovskaia et al 2021 Plasma Phys. Control. Fusion 63 054001) adopts an improved model for the magnetic drift frequency, which reduces the threshold magnetic island half-width from , where is the trapped ion banana orbit width, to , making it in closer agreement with experimental observations for the large aspect ratio tokamak equilibrium. In the present paper, the theory is extended to a high beta, arbitrary tokamak geometry to capture the plasma shaping effects on the NTM threshold physics with the focus on the non-zero triangularity discharges that are known to have a strong impact on the plasma MHD stability. First, it is found that the higher triangularity plasma is more prone to NTMs which is in agreement with the tearing mode onset relative frequency measurements in DIII-D. Second, the NTM threshold dependence on the tokamak inverse aspect ratio obtained in (Dudkovskaia et al 2021 Plasma Phys. Control. Fusion 63 054001) is refined and extended to a finite aspect ratio limit. Third, the NTM threshold dependence on poloidal beta is obtained and benchmarked against the EAST threshold island width measurements
The origins of the trypanosome genome strains Trypanosoma brucei brucei TREU 927, T. b. gambiense DAL 972, T. vivax Y486 and T. congolense IL3000
The genomes of several tsetse-transmitted African trypanosomes (Trypanosoma brucei brucei, T. b. gambiense, T. vivax, T. congolense) have been sequenced and are available to search online. The trypanosome strains chosen for the genome sequencing projects were selected because they had been well characterised in the laboratory, but all were isolated several decades ago. The purpose of this short review is to provide some background information on the origins and biological characterisation of these strains as a source of reference for future users of the genome data. With high throughput sequencing of many more trypanosome genomes in prospect, it is important to understand the phylogenetic relationships of the genome strains
Comparative proteomic profiling reveals mechanisms for early spinal cord vulnerability in CLN1 disease
CLN1 disease is a fatal inherited neurodegenerative lysosomal storage disease of early childhood, caused by mutations in the CLN1 gene, which encodes the enzyme Palmitoyl protein thioesterase-1 (PPT-1). We recently found significant spinal pathology in Ppt1-deficient (Ppt1−/−) mice and human CLN1 disease that contributes to clinical outcome and precedes the onset of brain pathology. Here, we quantified this spinal pathology at 3 and 7 months of age revealing significant and progressive glial activation and vulnerability of spinal interneurons. Tandem mass tagged proteomic analysis of the spinal cord of Ppt1−/−and control mice at these timepoints revealed a significant neuroimmune response and changes in mitochondrial function, cell-signalling pathways and developmental processes. Comparing proteomic changes in the spinal cord and cortex at 3 months revealed many similarly affected processes, except the inflammatory response. These proteomic and pathological data from this largely unexplored region of the CNS may help explain the limited success of previous brain-directed therapies. These data also fundamentally change our understanding of the progressive, site-specific nature of CLN1 disease pathogenesis, and highlight the importance of the neuroimmune response. This should greatly impact our approach to the timing and targeting of future therapeutic trials for this and similar disorders
Variation in the Structure of Bird Nests between Northern Manitoba and Southeastern Ontario
Traits that converge in appearance under similar environmental conditions among phylogenetically independent lineages are thought to represent adaptations to local environments. We tested for convergence in nest morphology and composition of birds breeding in two ecologically different locations in Canada: Churchill in northern Manitoba and Elgin in southeastern Ontario. We examined nests from four families of passerine birds (Turdidae: Turdus, Parulidae: Dendroica, Emberizidae: Passerculus and Fringillidae: Carduelis) where closely related populations or species breed in both locations. Nests of American Robins, Yellow Warblers, and Carduelis finches had heavier nest masses, and tended to have thicker nest-walls, in northern Manitoba compared with conspecifics or congenerics breeding in southeastern Ontario. Together, all species showed evidence for wider internal and external nest-cup diameters in northern Manitoba, while individual species showed varying patterns for internal nest-cup and external nest depths. American Robins, Yellow Warblers, and Carduelis finches in northern Manitoba achieved heavier nest masses in different ways. American Robins increased all materials in similar proportions, and Yellow Warblers and Common Redpolls used greater amounts of select materials. While changes in nest composition vary uniquely for each species, the pattern of larger nests in northern Manitoba compared to southeastern Ontario in three of our four phylogenetically-independent comparisons suggests that birds are adapting to similar selective pressures between locations
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