Spontaneous spinal epidural hematoma (SSEH) is a rare complication in patients of haemophilia. We report the case of a 9-year-old boy with severe haemophilia B who presented with acute abdomen of 5 days duration. Acute onset of neck/back pain,walking impairment and urinary retention has usually been described as symptom complex in SSEH. The hematoma was identified by magnetic resonance imaging of the spinal column. Our case calls attention to recognition of abdominal pain (with no other localizing features) as initial symptom of SSEH and prompt evaluation and management before more overt symptoms of spinal cord compression becomes evident.
Hemophilia B; Epidural hematoma; Acute abdomen
Fanconi’s Anemia is primarily an autosomal recessive genetic disorder characterized by congenital abnormalities, defective haematopoiesis leading to bone marrow failure and increased risk of development of Myelodysplastic syndrome, acute myeloid leukemia and solid tumours. Chromosomal instability can be demonstrated by breakage caused by alkylating agents and forms the basis of diagnosis. Our patient presented with structural deformities associated with features of bone marrow failure in form of pancytopenia. Bone marrow analysis and flow cytometry done on aspirate was suggestive of MDS. He subsequently progressed to frank acute myeloid leukemia and succumbed to the illness. The case is being reported for its rarity especially, Fanconi’s Anemia associated with monosomal karyotype (one monosomy plus one more structural abnormality).
Fanconi’s anemia; Chromosomal breakage syndrome; AML; Chromosomal anomalies
Pre-T cell acute lymphoblastic leukemia is a relatively rare leukemia. Twenty to 30 % of adult B cell leukemia cases are Philadelphia chromosome positive and it has a therapeutic and prognostic significance. Incidence and outcome of Ph+ T cell acute lymphoblastic leukemia (T cell ALL) is unknown. Only about 25 cases of de novo Ph+ T cell ALL and 44 cases of Ph+ T ALL in blastic phase of CML has been reported. Differentiation between Ph+ Pre-T ALL/LBL and T cell lymphoblastic crises of chronic myeloid leukemia may be difficult. We report a case of adult T cell ALL having Philadelphia chromosome as the cytogenetic abnormality. He was treated with acute lymphoblastic leukemia induction chemotherapy and Imatinib and achieved complete remission.
T cell acute lymphoblastic leukemia (T cell ALL); Philadelphia chromosome positive (Ph+)
Hemophagocytic lymphohistiocytosis (HLH) is a clinical condition which result in cytotoxic Tcell and antigen presenting cell overproduction and also their cytokines. Hepatitis A Virus associated HLH is very rare condition among other viruses. This condition is often difficult to diagnose, so treatment is often delayed. Here we present a case of adolescent boy with secondary virus associated HLH diagnosis with Hepatitis A infection and successfull treatment by short course of intravenous immunoglobulin and steroid.
Hepatitis A virus; Hemophagocytic lymphohistiocytosis; Children
Extranodal NK/Tcell lymphomas (ENKTL) are rare, aggressive lymphomas. The most common primary site of involvement is the nasal cavity, nasopharynx and paranasal sinuses. The other sites of primary involvement are skin, gastrointestinal tract and testis. Advanced disease can show lymph node, bone marrow and peripheral blood involvement. We report a case of ENKTL of the jejunum, showing peripheral pancytopenia and haemophagocytosis in the bone marrow. The intestine showed multiple intestinal perforations, with evidence of infiltration by lymphoma with coexistent strongyloides infestation. The patient showed disseminated disease in the form of lymphadenopathy and had a rapidly downhill course and expired on 5th day of admission. We also discuss the problems encountered by the pathologist in diagnosing these uncommon lymphomas.
Extranodal NK/Tcell lymphomas (ENKTL); Haemophagocytosis
Acquired haemophilia is a very rare condition, occurring in less than 2 per million populations. This condition is caused commonly by acquired antibodies against factor VIII and rarely by antibodies against factor IX. Here we describe an extremely rare presentation of idiopathic acquired haemophilia in an otherwise healthy male patient, caused by simultaneous occurrence of circulating antibodies against both factor VIII and IX.
Acquired haemophilia; Factor VIII inhibitor; Factor IX inhibitor
Transplant associated thrombotic microangiopathy is a severe complication of Hematopoeitic stem cell transplantation. Although there is agreement in terms of diagnostic criteria, treatment options are not clarified yet. We present a patient aged 2.6 years who developed transplant associated thrombotic microangiopathy after allogeneic bone marrow transplantation and to discuss both risk factors and possible spontaneous remission of transplant associated thrombotic microangiopathy.
Transplantation; Microangiopathy; Cyclosporine; CMV infection
Syntactic structure has been considered an integral component of
agreement computation in language production. In agreement error studies,
clause-boundedness (Bock & Cutting,
1992) and hierarchical feature-passing (Franck et al., 2002) predict that local nouns within
clausal modifiers should produce fewer errors than those within phrasal
modifiers due to structural differences; however, Gillespie and Pearlmutter (2011b) suggest structure may
play a more limited role. Two studies examined whether the clause-boundedness
effect would occur when prepositional phrase modifiers and relative clause
modifiers were matched in properties likely to influence timing of planning
(Gillespie & Pearlmutter; Solomon &
Pearlmutter, 2004). In both studies, more errors occurred for plural
local nouns, but the clause-boundedness effect was not observed. These findings
suggest that agreement computation during production does not involve a
clause-boundedness; hierarchical feature-passing; sentence production; speech errors; subject-verb agreement
I participated as an invited guest speaker at a Food and Drug Administration Advisory Panel meeting to provide expert background information on the potential clinical utility of dopaminergic neurons in the human brain. My conclusion at the end of the talk was that currently no clinical applications were justified. The purpose of the panel meeting was to advise the FDA regarding potential approval of a new drug application for a radiopharmaceutical that can be used to image dopaminergic pathways in the brain of living humans. After giving my presentation, I was permitted to observe the FDA and Pharma presentations but not permitted to ask or answer questions. This raises concerns about whether the FDA panel obtains a fair and unbiased review of the relevant data.
FDA; conflict of interest; expert testimony; neuroimaging; Parkinson disease
Smoking is causally associated with certain prevalent visually impairing eye diseases, including age-related macular degeneration and cataract. Studies have found that people are afraid of “going blind” and may be motivated to quit smoking if they know that vision loss is associated with smoking behavior.
A random-digit dialed telephone survey was used to measure health knowledge of adult smokers in Canada (n 5 2,765), the United States (n 5 3,178), the United Kingdom (n 5 2,767), and Australia (n 5 2,623) as part of the International Tobacco Control Four-Country Project.
A low proportion of smokers from Canada (13.0%), the United States (9.5%), and the United Kingdom (9.7%) believed that smoking can cause blindness. In contrast, 47.2% of Australian smokers believed that smoking causes blindness. Australia was the only country during the sampling period to have national awareness campaigns about smoking and its effects on eye health.
These findings point to the need across countries to educate the public on this important consequence of smoking. There is an opportunity for the public health and eye health communities to work to educate the public about the impacts smoking has on eye health to improve quit rates and help discourage people from starting to smoke.
public health; smoking; blindness; age-related macular degeneration; cataract
Neuronal variability plays a central role in neural coding and impacts the dynamics of neuronal networks. Unreliability of synaptic transmission is a major source of neural variability: synaptic neurotransmitter vesicles are released probabilistically in response to presynaptic action potentials and are recovered stochastically in time. The dynamics of this process of vesicle release and recovery interacts with variability in the arrival times of presynaptic spikes to shape the variability of the postsynaptic response. We use continuous time Markov chain methods to analyze a model of short term synaptic depression with stochastic vesicle dynamics coupled with three different models of presynaptic spiking: one model in which the timing of presynaptic action potentials are modeled as a Poisson process, one in which action potentials occur more regularly than a Poisson process (sub-Poisson) and one in which action potentials occur more irregularly (super-Poisson). We use this analysis to investigate how variability in a presynaptic spike train is transformed by short term depression and stochastic vesicle dynamics to determine the variability of the postsynaptic response. We find that sub-Poisson presynaptic spiking increases the average rate at which vesicles are released, that the number of vesicles released over a time window is more variable for smaller time windows than larger time windows and that fast presynaptic spiking gives rise to Poisson-like variability of the postsynaptic response even when presynaptic spike times are non-Poisson. Our results complement and extend previously reported theoretical results and provide possible explanations for some trends observed in recorded data.
Short term depression; Synaptic variability; Fano factor
Complex research questions often cannot be addressed adequately with a single data set. One sensible alternative to the high cost and effort associated with the creation of large new data sets is to combine existing data sets containing variables related to the constructs of interest. The goal of the present research was to develop a flexible, broadly applicable approach to the integration of disparate data sets that is based on nonparametric multiple imputation and the collection of data from a convenient, de novo calibration sample. We demonstrate proof of concept for the approach by integrating three existing data sets containing items related to the extent of problematic alcohol use and associations with deviant peers. We discuss both necessary conditions for the approach to work well and potential strengths and weaknesses of the method compared to other data set integration approaches.
harmonization; data set integration; missing data; multiple imputation
Understanding the mechanisms driving the extraordinary diversification of parasites is a major challenge in evolutionary biology. Co-speciation, one proposed mechanism that could contribute to this diversity is hypothesized to result from allopatric co-divergence of host–parasite populations. We found that island populations of the Galápagos hawk (Buteo galapagoensis) and a parasitic feather louse species (Degeeriella regalis) exhibit patterns of co-divergence across variable temporal and spatial scales. Hawks and lice showed nearly identical population genetic structure across the Galápagos Islands. Hawk population genetic structure is explained by isolation by distance among islands. Louse population structure is best explained by hawk population structure, rather than isolation by distance per se, suggesting that lice tightly track the recent population histories of their hosts. Among hawk individuals, louse populations were also highly structured, suggesting that hosts serve as islands for parasites from an evolutionary perspective. Altogether, we found that host and parasite populations may have responded in the same manner to geographical isolation across spatial scales. Allopatric co-divergence is likely one important mechanism driving the diversification of parasites.
population genetic structure; co-speciation; coevolution; co-divergence
Worldwide, many plant species are experiencing an earlier onset of spring phenophases due to climate warming. Rapid recent temperature increases on the Tibetan Plateau (TP) have triggered changes in the spring phenology of the local vegetation. However, remote sensing studies of the land surface phenology have reached conflicting interpretations about green-up patterns observed on the TP since the mid-1990s. We investigated this issue using field phenological observations from 1990 to 2006, for 11 dominant plants on the TP at the levels of species, families (Gramineae—grasses and Cyperaceae—sedges) and vegetation communities (alpine meadow and alpine steppe). We found a significant trend of earlier leaf-out dates for one species (Koeleria cristata). The leaf-out dates of both Gramineae and Cyperaceae had advanced (the latter significantly, starting an average of 9 days later per year than the former), but the correlation between them was significant. The leaf-out dates of both vegetation communities also advanced, but the pattern was only significant in the alpine meadow. This study provides the first field evidence of advancement in spring leaf phenology on the TP and suggests that the phenology of the alpine steppe can differ from that of the alpine meadow. These findings will be useful for understanding ecosystem responses to climate change and for grassland management on the TP.
leaf-out date; alpine meadow; alpine steppe; climate change; plant phenology; Tibetan Plateau
Understanding and predicting the outcomes of biological invasions is challenging where multiple invader and native species interact. We hypothesize that antagonistic interactions between invaders and natives could divert their impact on subsequent invasive species, thus facilitating coexistence. From field data, we found that, when existing together in freshwater sites, the native amphipod Gammarus duebeni celticus and a previous invader G. pulex appear to facilitate the establishment of a second invader, their shared prey Crangonyx pseudogracilis. Indeed, the latter species was rarely found at sites where each Gammarus species was present on its own. Experiments indicated that this may be the result of G. d. celticus and G. pulex engaging in more intraguild predation (IGP) than cannibalism; when the ‘enemy’ of either Gammarus species was present, that is, the other Gammarus species, C. pseudogracilis significantly more often escaped predation. Thus, the presence of mutual enemies and the stronger inter- than intraspecific interactions they engage in can facilitate other invaders. With some invasive species such as C. pseudogracilis having no known detrimental effects on native species, and indeed having some positive ecological effects, we also conclude that some invasions could promote biodiversity and ecosystem functioning.
intraguild predation; predator; prey; coexistence
Variability in metabolic scaling in animals, the relationship between metabolic rate (R) and body mass (M), has been a source of debate and controversy for decades. R is proportional to Mb, the precise value of b much debated, but historically considered equal in all organisms. Recent metabolic theory, however, predicts b to vary among species with ecology and metabolic level, and may also vary within species under different abiotic conditions. Under climate change, most species will experience increased temperatures, and marine organisms will experience the additional stressor of decreased seawater pH (‘ocean acidification’). Responses to these environmental changes are modulated by myriad species-specific factors. Body-size is a fundamental biological parameter, but its modulating role is relatively unexplored. Here, we show that changes to metabolic scaling reveal asymmetric responses to stressors across body-size ranges; b is systematically decreased under increasing temperature in three grazing molluscs, indicating smaller individuals were more responsive to warming. Larger individuals were, however, more responsive to reduced seawater pH in low temperatures. These alterations to the allometry of metabolism highlight abiotic control of metabolic scaling, and indicate that responses to climate warming and ocean acidification may be modulated by body-size.
metabolic scaling; ocean acidification; ecophysiology; metabolic allometry; MLB hypothesis
The social niche specialization hypothesis predicts that repeated social interactions will generate social niches within groups, thereby promoting consistent individual differences in behaviour. Current support for this hypothesis is mixed, probably because the importance of social niches is dependent upon the ecology of the species. We test whether repeated interactions among group mates generate consistent individual differences in boldness in the social spider, Stegodyphus dumicola. In support of the social niche specialization hypothesis, we found that consistent individual differences in boldness increased with longer group tenure. Interestingly, these differences took longer to appear than in previous work suggesting this species needs more persistent social interactions to shape its behaviour. Recently disturbed colonies were shyer than older colonies, possibly reflecting differences in predation risk. Our study emphasizes the importance of the social environment in generating animal personalities, but also suggests that the pattern of personality development can depend on subtle differences in species' ecologies.
social niche specialization; personality; Stegodyphus dumicola; social spider
On the steep surfaces that are common in arboreal environments, many types of animals without claws or adhesive structures must use muscular force to generate sufficient normal force to prevent slipping and climb successfully. Unlike many limbed arboreal animals that have discrete gripping regions on the feet, the elongate bodies of snakes allow for considerable modulation of both the size and orientation of the gripping region. We quantified the gripping forces of snakes climbing a vertical cylinder to determine the extent to which their force production favoured economy or safety. Our sample included four boid species and one colubrid. Nearly all of the gripping forces that we observed for each snake exceeded our estimate of the minimum required, and snakes commonly produced more than three times the normal force required to support their body weight. This suggests that a large safety factor to avoid slipping and falling is more important than locomotor economy.
locomotion; gripping pressure; normal force; prehensile; safety factor
The increased temperature associated with climate change may have important effects on body size and predator–prey interactions. The consequences of these effects for food web structure are unclear because the relationships between temperature and aspects of food web structure such as predator–prey body-size relationships are unknown. Here, we use the largest reported dataset for marine predator–prey interactions to assess how temperature affects predator–prey body-size relationships among different habitats ranging from the tropics to the poles. We found that prey size selection depends on predator body size, temperature and the interaction between the two. Our results indicate that (i) predator–prey body-size ratios decrease with predator size at below-average temperatures and increase with predator size at above-average temperatures, and (ii) that the effect of temperature on predator–prey body-size structure will be stronger at small and large body sizes and relatively weak at intermediate sizes. This systematic interaction may help to simplify forecasting the potentially complex consequences of warming on interaction strengths and food web stability.
global warming; temperature; food web structure; body-size ratios; temperature size rule
Mechanisms of aerial righting in juvenile chukar partridge (Alectoris chukar) were studied from hatching to 14 days-post-hatching (dph). Asymmetric movements of the wings were used from 1 to 8 dph to effect progressively more successful righting behaviour via body roll. Following 8 dph, wing motions transitioned to bilaterally symmetric flapping that yielded aerial righting via nose-down pitch, along with substantial increases in vertical force production during descent. Ontogenetically, the use of such wing motions to effect aerial righting precedes both symmetric flapping and a previously documented behaviour in chukar (i.e. wing-assisted incline running) hypothesized to be relevant to incipient flight evolution in birds. These findings highlight the importance of asymmetric wing activation and controlled aerial manoeuvres during bird development and are potentially relevant to understanding the origins of avian flight.
aerodynamics; control; development; flight origins; manoeuvrability; wing
Human transportation facilitates the dispersal of exotic ants, but few studies have quantified the magnitude and geography of these movements. We used several non-parametric indices to estimate the number of species successfully introduced to or established in new regions. We also compared their source biogeographic realms to assess the importance of geographical origin in determining the likelihood of establishment after introduction. Occurrence data on exotic ants derive from studies of three temperate regions. Our results suggest that the numbers of introduced or established ants may be much larger than the numbers so far documented. Ants introduced or established in new regions tend to arrive from the same or neighbouring realms, as would be expected if exotic species tend to match climates and if arrival/establishment is dependent upon higher trade rates from neighbouring countries.
biological invasions; exotic species; formicidae; richness estimator
In many ecological situations, resources are difficult to find but become more apparent to nearby searchers after one of their numbers discovers and begins to exploit them. If the discoverer cannot monopolize the resources, then others may benefit from joining the discoverer and sharing their discovery. Existing theories for this type of conspecific attraction have often used very simple rules for how the decision to join a discovered resource patch should be influenced by the number of individuals already exploiting that patch. We use a mechanistic, spatially explicit model to demonstrate that individuals should not necessarily simply join patches more often as the number of individuals exploiting the patch increases, because those patches are likely to be exhausted soon or joining them will intensify future local competition. Furthermore, we show that this decision should be sensitive to the nature of the resource patches, with individuals being more responsive to discoveries in general and more tolerant of larger numbers of existing exploiters on a patch when patches are resource-rich and challenging to locate alone. As such, we argue that this greater focus on underlying joining mechanisms suggests that conspecific attraction is a more sophisticated and flexible tactic than currently appreciated.
conspecific attraction; genetic algorithm; population size; spatial resource heterogeneity
The oxytocin (OT) family of neuropeptides are known to modulate social behaviours and anxiety in mammals and birds. We investigated cell numbers and neural activity, assessed as Fos induction, within magnocellular and parvocellular populations of neurons producing the OT homologue mesotocin (MT, Ile8-oxytocin). This was conducted within the male brown anole lizard, Anolis sagrei, following agonistic or courtship encounters with a conspecific. Both neurons colocalizing and not colocalizing corticotropin-releasing factor (CRF) were examined. Parvocellular neurons of the paraventricular nucleus exhibited a positive correlation between courtship frequency and Fos colocalization, regardless of whether they produce just MT or MT + CRF. Magnocellular populations showed only trends towards positive relationships with courtship and no cell populations showed aggression-related Fos induction. These findings are novel because they demonstrate the involvement of MT neurons in male social behaviour, especially in reptiles for whom the involvement of MT in social behaviour was previously unknown.
mesotocin; oxytocin; corticotropin-releasing factor; anole lizard; aggression; courtship
Paralleling behaviours in other species, synchronized movement is central to institutionalized collective human activities thought to enhance cooperation, and experiments demonstrate that synchrony has this effect. The influence of synchrony on cooperation may derive from an evolutionary history wherein such actions served to signal coalitional strength to both participants and observers—including adversaries. If so, then synchronous movement should diminish individuals' estimations of a foe's formidability. Envisioned physical size and strength constitute the dimensions of a representation that summarizes relative fighting capacity. Experiencing synchrony should therefore lead individuals to conceptualize an antagonist as smaller and weaker. We found that men who walked synchronously with a male confederate indeed envisioned a purported criminal as less physically formidable than did men who engaged in this task without synchronizing.
synchrony; alliance; fighting capacity