The difference conservation makes to extinction risk of the world's ungulates.

Previous studies show that conservation actions have prevented extinctions, recovered populations, and reduced declining trends in global biodiversity. However, all studies to date have substantially underestimated the difference conservation action makes because they failed to account fully for what would have happened in the absence thereof. We undertook a scenario-based thought experiment to better quantify the effect conservation actions have had on the extinction risk of the world's 235 recognized ungulate species. We did so by comparing species' observed conservation status in 2008 with their estimated status under counterfactual scenarios in which conservation efforts ceased in 1996. We estimated that without conservation at least 148 species would have deteriorated by one International Union for Conservation of Nature (IUCN) Red List category, including 6 species that now would be listed as extinct or extinct in the wild. The overall decline in the conservation status of ungulates would have been nearly 8 times worse than observed. This trend would have been greater still if not for conservation on private lands. While some species have benefited from highly targeted interventions, such as reintroduction, most benefited collaterally from conservation such as habitat protection. We found that the difference conservation action makes to the conservation status of the world's ungulate species is likely to be higher than previously estimated. Increased, and sustained, investment could help achieve further improvements.

Internal and external carotid vascular responses to vasoactive agents in the monkey.

Internal and external carotid blood flows in anesthetized monkeys were measured simultaneously using electromagnetic flowmeters. Complete dose-response relationships were established for the effects of intracarotid infusion of several humoral agents implicated in migraine. Both the internal and external carotid vasculatures were constricted by serotonin and prostaglandin F2alpha and dilated by bradykinin, histamine, and acetylcholine. Noradrenalin and adrenaline constricted the external carotid vasculature but had little direct effect in the internal carotid territory. Prostaglandin E1 dilated the external carotid vasculature. Low doses of prostaglandin E1 produced dilation in the internal carotid circulation, but with higher doses there was a paradoxical abolition of this effect.

Low frequency stimulation of the locus coeruleus reduces regional cerebral blood flow in the spinalized cat.

Regional cerebral blood flow (RCBF) was studied during low frequency (15/s) and high frequency (50/s) electrical stimulation of the locus coeruleus (LC) in the alpha-chloralose-anesthetized cat using the freely diffusible tracer [14C]iodoantipyrine and regional brain dissection. The responses were determined in animals spinalized at the C1/C2 level to eliminate systemic effects of pontine stimulation such as alterations in blood pressure and heart rate. The spinalization, itself, did not alter resting RCBF or reactivity to hypercapnia. Low frequency stimulation reduced regional cerebral blood flow in the cortex, basal ganglia and white matter of the corpus callosum. The reductions in RCBF were maximal (35%) in the occipital cortex whereas no changes were seen in the colliculi. No changes were seen in any brain areas with high frequency stimulation. The relevance of this brainstem effect on cerebral blood flow to pathological states such as stroke and migraine is discussed.

Comparative effects of stimulation of the trigeminal ganglion and the superior sagittal sinus on cerebral blood flow and evoked potentials in the cat.

The superior sagittal sinus (SSS) and the trigeminal ganglion (Vg) of anesthetized cats were stimulated electrically and field potentials in the upper cervical spinal cord and regional cerebral blood flow were recorded. Stimulation of the entire ganglion produced smaller field potential changes in two regions (medioventral area (MVA); dorsolateral area (DLA] of the upper spinal cord than did stimulation of the sagittal sinus (Vg/SSS response ratio = 17% for the MVA and 48% for the DLA). Stimulation of the trigeminal ganglion increased blood flow in only the frontal and parietal cortices (+93% and +33%), whereas stimulation of the sinus produced both larger changes in these areas (+137% and +139%) and also produced changes in regional cerebral blood flow in the thalamus (+122%).

Low pharmacological responsiveness of the vertebro-basilar circulation in Macaca nemestrina monkeys.

We have examined the responsiveness of the vertebro-basilar circulation of the anesthetized Macaca nemestrina monkey to vasoactive agents infused directly into the artery. Infusion of noradrenaline caused a slight increase in vertebral arterial resistance. This constriction was less than that seen in previous experiments with either the internal or vertebral arterial resistance. This constriction was less than that seen in previous experiments with either the internal or external carotid arteries. In the presence of vasodilatation caused by inhalation of a CO2-rich gas mixture, this constriction became a dilatation. Serotonin was without significant effect on the vertebral arterial bed. Bradykinin, histamine and prostaglandin E1 all produced slight dilatation, with bradykinin being the most potent. In all cases the concentration required to produce an effect on the vasculature was much greater in the vertebral circulation than it is in the internal carotid and extracerebral circulations. We conclude that the intact vertebro-basilar circulation is much less sensitive to vasoactive agents than experiments with isolated segments of these arteries would indicate and that therefore these agents are unlikely to play a significant part in the pathogenesis of vertebro-basilar migraine.

Effects of low doses of clonidine in the monkey cranial circulation.

Migraine therapy using low doses of clonidine has been based on the proposal that clonidine directly inhibits vascular smooth muscle reactivity. In anaesthetized monkeys in which internal and external carotid vascular resistances were measured, the only significant effects of clonidine administered acutely (0.5 and 2 microgram x kg-1 i.v.) or chronically (2 microgram x kg-1 i.m. daily for 7 days) on cranial vascular responses to the constrictors noradrenaline and 5-hydroxytryptamine, and the dilators histamine, prostaglandin E1 and bradykinin, were small potentiations of some of the responses. Acute clonidine initially increased blood pressure and constricted the cranial vasculature, then induced hypotension without involvement of the cranial circulation. It also decreased the external carotid vasoconstrictor response to low frequency cervical sympathetic nerve stimulation. The low chronic dose of clonidine had no hypotensive effect. The pressor response to common carotid occlusion was inhibited by both acute and chronic clonidine. These experiments thus provide no evidence that clonidine inhibits cranial vascular reactivity at doses equivalent to those used in migraine.

Effects of methysergide, pizotifen and ergotamine in the monkey cranial circulation.

Internal and external carotid vascular resistances were measured, in anaesthetized monkeys, to asses the direct cranial vascular effects of i.v. methysergide, pizotifen and ergotamine, and their effects on the cranial vascular responses to the constrictors 5-hydroxytryptamine and noradrenaline and the dilators histamine, prostaglandin E1 and bradykinin. Methysergide reduced responses to 5-HT, and tended to potentiate the external carotid responses to noradrenaline. Pizotifen blocked responses to histamine; it tended to reduce internal carotid responses to 5-HT, but it potentiated external carotid 5-HT responses. Ergotamine reduced responses to 5-HT and noradrenaline, but this was probably related to its cranial vasoconstrictor effects, especially in the external carotid circulation. Methysergide induced weak transient cranial vasoconstriction and pizotifen had no direct effects. These findings may be relevant to the therapeutic actions of these drugs in migraine, since the doses used approximated to those used clinically.

Decreased carotid arterial resistance in cats in response to trigeminal stimulation.

Stimulation of the trigeminal nerve or ganglion in the cat caused a frequency-dependent reduction in carotid vascular resistance. Systemic arterial blood pressure (SABP) decreased at low frequencies (0.2 to 5 sec-1) and increased at higher frequencies, thus increasing carotid blood flow at the higher frequencies. The effect on resistance was predominantly ipsilateral and was unaltered by cervical sympathectomy, but was abolished or substantially reduced by section of the trigeminal root proximal to the ganglion. Diminution of carotid vascular resistance was replicated by stimulation of the greater superficial petrosal (GSP) nerve without any change in SABP. Section of the seventh cranial nerve reduced or abolished the response to stimulation of the trigeminal nerve but not that from the GSP nerve. The trigeminal response was prevented by ganglion-blocking drugs in seven out of eight cats. The resistance response was unaffected by noradrenergic, cholinergic, serotonergic, and histamine-2 blocking agents. No neural connection could be demonstrated between the GSP and the trigeminal ganglion, and the vascular response to GSP stimulation persisted after trigeminal section. It is concluded that activation of the trigeminal system increases carotid blood flow by a pathway involving the seventh cranial nerve, the GSP and Vidian nerves, and a parasympathetic synapse employing an unconventional transmitter. A varying proportion of the response (greatest in the third division) may be mediated by antidromic activation of trigeminal nerves. These findings may have clinical implications for the vascular changes of migraine and other facial pain.

Influence of environmental conditions on a new surfactant-based contrast agent: ST68.

Environmental influences on the new surfactant-stabilized bubbles, ST68, were investigated. We have developed a new surfactant-based contrast agent ST68, which is prepared by insonating buffered mixtures of Span 60 and Tween 80 in the presence of either air, PFC, or SF(6) gas. The effect of dilution, shear, and sonication on size distribution of ST68 showed that PFC-containing bubbles (ST68-PFC) were most stable. ST68-PFC bubbles lasted more than 15 min with approximately 30 dB backscatter enhancement in degassed phosphate-buffered saline, (pH 7.4), and air bubbles lasted approximately 3 s, suggesting the effects of diffusion. Additionally, it was found that the ionic strength of the suspending medium (for example, PBS), did not have any effect on ST68 bubbles containing SF(6) or PFC, but had a dramatic impact on bubbles containing air.

Modelling the species distribution of flat-headed cats (Prionailurus planiceps), an endangered South-East Asian small felid.

BACKGROUND: The flat-headed cat (Prionailurus planiceps) is one of the world's least known, highly threatened felids with a distribution restricted to tropical lowland rainforests in Peninsular Thailand/Malaysia, Borneo and Sumatra. Throughout its geographic range large-scale anthropogenic transformation processes, including the pollution of fresh-water river systems and landscape fragmentation, raise concerns regarding its conservation status. Despite an increasing number of camera-trapping field surveys for carnivores in South-East Asia during the past two decades, few of these studies recorded the flat-headed cat. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we designed a predictive species distribution model using the Maximum Entropy (MaxEnt) algorithm to reassess the potential current distribution and conservation status of the flat-headed cat. Eighty-eight independent species occurrence records were gathered from field surveys, literature records, and museum collections. These current and historical records were analysed in relation to bioclimatic variables (WorldClim), altitude (SRTM) and minimum distance to larger water resources (Digital Chart of the World). Distance to water was identified as the key predictor for the occurrence of flat-headed cats (>50% explanation). In addition, we used different land cover maps (GLC2000, GlobCover and SarVision LLC for Borneo), information on protected areas and regional human population density data to extract suitable habitats from the potential distribution predicted by the MaxEnt model. Between 54% and 68% of suitable habitat has already been converted to unsuitable land cover types (e.g. croplands, plantations), and only between 10% and 20% of suitable land cover is categorised as fully protected according to the IUCN criteria. The remaining habitats are highly fragmented and only a few larger forest patches remain. CONCLUSION/SIGNIFICANCE: Based on our findings, we recommend that future conservation efforts for the flat-headed cat should focus on the identified remaining key localities and be implemented through a continuous dialogue between local stakeholders, conservationists and scientists to ensure its long-term survival. The flat-headed cat can serve as a flagship species for the protection of several other endangered species associated with the threatened tropical lowland forests and surface fresh-water sources in this region.

The status of the world's land and marine mammals: diversity, threat, and knowledge.

Knowledge of mammalian diversity is still surprisingly disparate, both regionally and taxonomically. Here, we present a comprehensive assessment of the conservation status and distribution of the world's mammals. Data, compiled by 1700+ experts, cover all 5487 species, including marine mammals. Global macroecological patterns are very different for land and marine species but suggest common mechanisms driving diversity and endemism across systems. Compared with land species, threat levels are higher among marine mammals, driven by different processes (accidental mortality and pollution, rather than habitat loss), and are spatially distinct (peaking in northern oceans, rather than in Southeast Asia). Marine mammals are also disproportionately poorly known. These data are made freely available to support further scientific developments and conservation action.

Effect of stimulation of trigeminal ganglion on regional cerebral blood flow in cats.

Regional cerebral blood flow was studied in the cat, with and without trigeminal ganglion stimulation, by the intravenous injection of the tracer [14C]iodoantipyrine and subsequent regional brain dissection. Electrical activation of the trigeminal ganglion led to a selective increase in regional blood flow in the frontal and parietal cortex that was bilateral without change in the posterior cortex, deep cerebral nuclei, white matter, or brain stem. Unilateral intracranial section of the facial nerve blocked the response in the ipsilateral frontal and parietal cortex, whereas bilateral facial nerve section blocked the contralateral frontal cortical response. The contralateral parietal cortical increase in blood flow was not affected by facial nerve section and may thus represent the result of metabolic activation of sensory cortex.

Position of ultimobranchial body cysts in the human fetal thyroid gland.

In a series of 21 human fetal thyroid glands examined histologically in serial sections, seven ultimobranchial body cysts were found. The position of these cysts correlated well with the distribution of calcitonin-containing cells found by previous investigators in the adult thyroid gland. Ultimobranchial body cysts found external to the thyroid lobes may offer a developmental explanation for the paucity of calcitonin found in some adult thyroid glands. The close developmental relationship between the parathyroid gland and the ultimobranchial body could explain the presence of calcitonin found in these glands in some adults.

Ultimobranchial body cysts in the human foetal thyroid: pathological implications.

In a histological study of 28 human foetal thyroids, ultimobranchial body cysts were found in seven foetuses. Large oval cells were seen adjacent to or within the cysts. There is a morphological resemblance between the cells associated with the ultimobranchial cysts and those of medullary carcinoma of the thyroid gland. This similarity, in humans, substantiates the hypothesis that medullary carcinoma arises from the parafollicular cells, which themselves are known to differentiate from ultimobranchial body tissue.

Cortical blood flow changes during spreading depression in cats.

Changes in cortical blood flow and cerebrovascular activity occurring during and after cortical spreading depression (CSD) were studied in alpha-chloralose-urethan-anesthetized cats. CSD was induced by superficial cortical pinprick, and laser-Doppler velocimetry (LDV) was used to measure cerebral blood flow (CBFLD). CSD resulted in a wave of cortical hyperemia during which there was a 215 +/- 48% peak increase in cortical blood flow that lasted for 2.7 +/- 0.4 min. This hyperemic phase was followed by prolonged cortical oligemia, with a reduction in flow of 20 +/- 4% at 1 h and 28 +/- 4% at 2 h. After CSD, cerebrovascular reactivity to the inhalation of CO2 was abolished and did not fully recover for at least 10 h. Spontaneous vasomotor activity in the cerebral microcirculation was significantly decreased after CSD, and autoregulation of cortical blood flow in response to hypotension was preserved. The abnormal cerebrovascular reactivity seen after CSD in the gyrencephalic cortex of the cat has possible significance for human migraine with aura.

The anatomy and physiology of the vertebral nerve in relation to cervical migraine.

The anatomy of the vertebral nerve was investigated in humans and in monkeys. The effect of stimulation of the vertebral nerve and the cervical sympathetic trunk in the monkey was studied. The vertebral nerves in man and monkey represent a series of deep grey rami communicantes which form intersegmental neural arcades around the vertebral artery between C7 and C3. Above C3 the vertebral artery is accompanied by direct branches from the C1-3 ventral rami. Electrical stimulation of either the vertebral nerve or the cervical sympathetic trunk had a minimal effect on vertebral blood flow. In contrast, sympathetic stimulation had pronounced effects on carotid flow and resistance. Anatomically and physiologically there are no grounds to support the hypothesis that irritation of the "vertebral nerve" is the pathogenetic mechanism of cervical migraine.

Motor neuron disease in Australia (State of New South Wales).

The case histories of 70 patients with typical motor neuron disease (MND) have been analysed to ascertain the natural history of the disease in Australia. The place of birth and residence during life of each patient has been sought to determine whether there is any 'clustering' of patients in the State of New South Wales. The mean age of onset was 55 years and mean duration of life from onset was 3 years 5 months. These figures are comparable with those from the USA and UK and Japan although the onset in Australia was later and the duration longer. The case history of 1 patient who is still living 38 years after the onset of the disease is described as there is no longer survival time recorded in the literature to our knowledge. Attention is drawn to muscle aches and cramps mentioned spontaneously by 27 of the 70 patients. These symptoms occurred at the onset of MND and often correlated with the site of onset of weakness. Weight loss averaged 1.6lb (0.7kg) per month in those patients in whom weight was recorded. The CSF protein was greater than 45mg/100ml, ranging up to 110mg/100ml, in 9 of 37 patients. The place of residence of patients bore no relation to known areas of increased manganese in the soil, and there was no evidence of 'clustering' of cases.

Complement activation in migraine.

Forty patients attending the Prince Henry Hospital migraine clinic have been investigated for evidence of complement activation related to migraine. These patients had a history of clinically similar migraine attacks. Levels of serum complement components were determined in nine patients, both in and out of migraine. Comparison of these levels showed significant reductions in C4 and C5 during headache. In a further 31 patients C3 breakdown products were sought when these patients were headache-free. They were detected in the plasma of three patients who proceeded to a migraine attack but not in the plasma of the remaining twenty-eight who did not. These findings suggest the presence of complement activation, which could explain many of the previously reported phenomena associated with migraine.

Aminergic histofluorescence and contractile responses to transmural electrical field stimulation and norepinephrine of human middle cerebral arteries obtained promptly after death.

The responses of cerebral arteries to catecholamines and sympathetic nerve stimulation show wide variation between animal species. We examined the catecholaminergic histofluorescence and the contractile responses elicited by transmural electrical field stimulation and norepinephrine (NE) in proximal segments of human middle cerebral artery (MCA) obtained during autopsy. Twenty-four percent of the specimens were obtained within 2 hours and 76% within 4 hours of death. A moderately dense catecholaminergic histofluorescence was seen in all segments of human MCA using the glyoxylic acid technique, counterstained with pontamine sky blue. However, only seven of 35 (20%) MCA segments tested showed tetrodotoxin-blocked transmural electrical field stimulation contractions, and all of these were harvested within 4 hours of death. The responses were mostly seen in the most proximal MCA segments and, at 32 Hz, only achieved 6 +/- 1% of the maximal tissue contraction. NE caused two distinct responses in human MCA segments. At low concentrations, it acts via an alpha-like adrenoreceptor to cause contractions 20 +/- 3% of the maximal tissue response. The NE ED50s for the three successive segments were not different from each other; the value for the most-proximal segment was 7.9 +/- 0.2 x 10(-7) M. At concentrations above 10(-5) M, this catecholamine acts on low-affinity sites resistant to alpha-adrenergic antagonists causing contractions that at 10(-3) M reach 52 +/- 5% of the maximal tissue response.(ABSTRACT TRUNCATED AT 250 WORDS)