How do invasive predators and their native prey respond to prescribed fire?

Fire shapes animal communities by altering resource availability and species interactions, including between predators and prey. In Australia, there is particular concern that two highly damaging invasive predators, the feral cat (Felis catus) and European red fox (Vulpes vulpes), increase their activity in recently burnt areas and exert greater predation pressure on the native prey due to their increased exposure. We tested how prescribed fire occurrence and extent, along with fire history, vegetation, topography, and distance to anthropogenic features (towns and farms), affected the activity (detection frequency) of cats, foxes, and the native mammal community in south-eastern Australia. We used camera traps to quantify mammal activity before and after a prescribed burn and statistically tested how the fire interacted with these habitat variables to affect mammal activity. We found little evidence that the prescribed fire influenced the activity of cats and foxes and no evidence of an effect on kangaroo or small mammal (<800 g) activity. Medium-sized mammals (800-2000 g) were negatively associated with prescribed fire extent, suggesting that prescribed fire has a negative impact on these species in the short term. The lack of a clear activity increase from cats and foxes is likely a positive outcome from a fire management perspective. However, we highlight that their response is likely dependent upon factors like fire size, severity, and prey availability. Future experiments should incorporate GPS-trackers to record fine-scale movements of cats and foxes in temperate ecosystems immediately before and after prescribed fire to best inform management within protected areas.

Impact of hyperleptinemia during placental ischemia-induced hypertension in pregnant rats.

The prevalence of preeclampsia and obesity have increased. Although obesity is a major risk factor for preeclampsia, the mechanisms linking these morbidities are poorly understood. Circulating leptin levels increase in proportion to fat mass. Infusion of this adipokine elicits hypertension in nonpregnant rats, but less is known about how hyperleptinemia impacts blood pressure during placental ischemia, an initiating event in the pathophysiology of hypertension in preeclampsia. We tested the hypothesis that hyperleptinemia during reduced uterine perfusion pressure (RUPP) exaggerates placental ischemia-induced hypertension. On gestational day (GD) 14, Sprague-Dawley rats were implanted with osmotic mini-pumps delivering recombinant rat leptin (1 µg/kg/min iv) or vehicle concurrently with the RUPP procedure to induce placental ischemia or Sham. On GD 19, plasma leptin was elevated in Sham + Leptin and RUPP + Leptin. Leptin infusion did not significantly impact mean arterial pressure (MAP) in Sham. MAP was increased in RUPP + Vehicle vs. Sham + Vehicle. In contrast to our hypothesis, placental ischemia-induced hypertension was attenuated by leptin infusion. To examine potential mechanisms for attenuation of RUPP-induced hypertension during hyperleptinemia, endothelial-dependent vasorelaxation to acetylcholine was similar between Sham and RUPP; however, endothelial-independent vasorelaxation to the nitric oxide (NO)-donor, sodium nitroprusside, was increased in Sham and RUPP. These findings suggest that NO/cyclic guanosine monophosphate (cGMP) signaling was increased in the presence of hyperleptinemia. Plasma cGMP was elevated in Sham and RUPP hyperleptinemic groups compared with vehicle groups but plasma and vascular NO metabolites were reduced. These data suggest that hyperleptinemia during placental ischemia attenuates hypertension by compensatory increases in NO/cGMP signaling.NEW & NOTEWORTHY Ours is the first study to examine the impact of hyperleptinemia on the development of placental ischemia-induced hypertension using an experimental animal model.

Administration of recombinant human placental growth factor decreases blood pressure in obese hypertensive pregnant rats.

OBJECTIVES: Although epidemiological studies have shown that obesity is associated with increased incidence of hypertension during pregnancy, the mechanisms linking these two comorbidities are not as well studied. Previous investigations detected lower levels of the anti-hypertensive and pregnancy-related factor, placental growth factor (PlGF), in obese hypertensive pregnancies. Therefore, we examined whether obese hypertensive pregnant rats have reduced PlGF and whether increasing its levels by administering recombinant human (rh)PlGF reduces their blood pressure. METHODS: We utilized a genetic model of obesity characterized to be heavier, hypertensive and fertile, namely rats having heterozygous deficiency of the melanocortin-4 receptor (MC4R-def). RESULTS: MC4R-def obese rats had lower circulating levels of PlGF than wild-type lean controls at gestational day 19. Also, assessment of the PlGF receptor, Flt-1, in the vasculature showed that its levels were reduced in aorta and kidney glomeruli but increased in small mesenteric arteries. Chronic intraperitoneal administration of rhPlGF from gestational day 13-19 significantly increased circulating PlGF levels in both obese and lean rats, but reduced blood pressure only in the obese pregnant group. The rhPlGF treatment did not alter maternal body and fat masses or circulating levels of the adipokines, leptin and adiponectin. In addition, this treatment did not impact average foetal weights but increased placental weights regardless of obese or lean pregnancy. CONCLUSION: PlGF is reduced in MC4R-def obese hypertensive pregnant rats, which is similar to findings in obese hypertensive pregnant women, while increasing its levels with exogenous rhPlGF reduces their blood pressure.

Paranoid delusions • ideas of reference • sleep problems • Dx?

► Paranoid delusions ► Ideas of reference ► Sleep problems ► Multiple, vague somatic symptoms.

Does a regular Wessex Head Injury Matrix assessment identify early signs of infections in people with Prolonged Disorders of Consciousness?

BACKGROUND & OBJECTIVE: Patients with brain injury are at high risk for infections. Although infection and cognitive deterioration are established for people with dementia, this has not been shown for patients with a prolonged disorder of consciousness (PDOC). This study determines whether regular Wessex Head Injury Matrix (WHIM) assessments can identify early signs of infections in patients with PDOC. METHOD: Retrospective and prospective approaches were used to assess the WHIM scores of patients with a PDOC (N = 21 in the retrospective study and 22 in the prospective study). RESULTS: The WHIM total scores decreased due to infections in 17 of the 21 cases of infection (p < 0.001) in the retrospective study and 15 (p = 0.001) of the 22 prospective cases of infection. Patients in a minimally conscious state (MCS) showed a bigger proportion of change between their baseline score and the scores taken in the pre-infection stage in both the retrospective and prospective studies when compared to patients in a vegetative state (VS). CONCLUSION: The findings suggest the importance of serial WHIM assessments throughout the period of recovery, not only to measure cognitive changes but also to highlight underlying physical changes such as infections that will impact the response to rehabilitation and recovery.

Demographic and genetic viability of a medium-sized ground-dwelling mammal in a fire prone, rapidly urbanizing landscape.

The rapid and large-scale urbanization of peri-urban areas poses major and complex challenges for wildlife conservation. We used population viability analysis (PVA) to evaluate the influence of urban encroachment, fire, and fauna crossing structures, with and without accounting for inbreeding effects, on the metapopulation viability of a medium-sized ground-dwelling mammal, the southern brown bandicoot (Isoodon obesulus), in the rapidly expanding city of Perth, Australia. We surveyed two metapopulations over one and a half years, and parameterized the PVA models using largely field-collected data. The models revealed that spatial isolation imposed by housing and road encroachment has major impacts on I. obesulus. Although the species is known to persist in small metapopulations at moderate levels of habitat fragmentation, the models indicate that these populations become highly vulnerable to demographic decline, genetic deterioration, and local extinction under increasing habitat connectivity loss. Isolated metapopulations were also predicted to be highly sensitive to fire, with large-scale fires having greater negative impacts on population abundance than small-scale ones. To reduce the risk of decline and local extirpation of I. obesulus and other small- to medium-sized ground-dwelling mammals in urbanizing, fire prone landscapes, we recommend that remnant vegetation and vegetated, structurally-complex corridors between habitat patches be retained. Well-designed road underpasses can be effective to connect habitat patches and reduce the probability of inbreeding and genetic differentiation; however, adjustment of fire management practices to limit the size of unplanned fires and ensure the retention of long unburnt vegetation will also be required to ensure persistence. Our study supports the evidence that in rapidly urbanizing landscapes, a pro-active conservation approach is required that manages species at the metapopulation level and that prioritizes metapopulations and habitat with greater long-term probability of persistence and conservation capacity, respectively. This strategy may help us prevent future declines and local extirpations, and currently relatively common species from becoming rare.

Brugada syndrome and the story of Dave.

Brugada syndrome (BrS) is a little known genetic condition that causes severe disturbances in cardiac rhythm and may result in sudden unexpected cardiac death in an apparently healthy person. The heart structure is typically normal but there are problems with electrical activity. The syndrome is named after Spanish brothers who are cardiologists, Pedro and Josep Brugada. BrS is the major cause of sudden unexplained death syndrome (SUDS), also known as sudden arrhythmic death syndrome (SADS). Following a description of the syndrome, including its prevalence and incidence, how it is diagnosed and how it can be treated, we consider those who survive a cardiac arrest and what problems they may face. Most publications focus on the medical aspects of BrS but, of course, cardiac arrest can result in hypoxic brain damage. We conclude with the story of Dave, a 25-year-old man diagnosed with BrS following a nose bleed and subsequent cardiac arrest. He was left with a visual impairment, dystonia, hypersensitivity, and language and cognitive dysfunction. We look at Dave's strengths and weaknesses, his response to offered treatment, and his consequent improvement. We stress the contributions from members of the multidisciplinary team and offer suggestions for the rehabilitation of other survivors of BrS.

Akinetic mutism and the story of David.

Following a description about the characteristics of akinetic mutism (AM) and how it differs from locked-in syndrome (LIS) and a disorder of consciousness (DOC), we present the case of David, a 71-year-old man with AM. David sustained a stroke following a middle cerebral artery (MCA) thrombus. A CT scan at the time detected old ischaemic infarcts affecting the right frontal lobe, the left occipital lobe and the left parietal lobe so David had bilateral brain damage. Initially thought to have a DOC, further neuropsychological assessments administered when David had improved a little, resulted in the diagnosis of AM. Although David spoke little, when he did speak, his words and phrases were well articulated, grammatical and with appropriate intonation. He was alert and visually aware and he was not paralysed. We discuss whether the diagnosis was correct and address the difficulties in assessing such patients.

Sheehan's syndrome and sickle cell disease: the story of Natasha.

Sheehan's syndrome (SS) is one of the pituitary disorders caused by severe blood loss during childbirth leading to necrosis of the pituitary gland. Diagnosis is made following severe haemorrhage, failure to produce milk and failure to menstruate. Rare in countries with good obstetric care, SS is still frequent in those countries with poor healthcare services. The majority of papers published on SS do not mention psychological or neuropsychological sequelae. Of those that do, mood disorders are sometimes reported and occasionally cognitive problems are noted, typically attention, memory or executive deficits. We report on Natasha, a British woman of Caribbean ancestry with sickle cell disease (SCD), diagnosed at age 33 years with SS following the birth of her second child. We know of no reports of a person with both SCD and SS. Natasha has been seen regularly for neuropsychological assessment and treatment for over two years. There has been a slight increase in her cognitive functioning but she remains with Balint's syndrome, so is unable to read. Treatment for this has been partially successful. Natasha presented with psychotic type symptoms when first seen but these have improved to a large extent. We believe that these symptoms are consistent with SS but the severe cognitive problems are more likely to be due to the strokes she suffered at the time of the haemorrhage and, possibly, to hypoxic damage caused by very low blood pressure.

TD: The case of Diogenes Syndrome-deficit or denial?

Diogenes Syndrome (DS) is characterised by extreme self-neglect, domestic squalor, hoarding, social withdrawal, and lack of concern and shame for the individual's residential situation. This paper describes TD who was unable to identify emotional expressions of disgust and was borderline-impaired for facial recognition associated with perceptual difficulties. Problems interpreting expressions of disgust were interesting as TD was living in squalor, neglecting himself, and lacked concern for his circumstances. This led us to question whether the basis of his difficulties were neuropsychological or psychological in nature, which became the objective of this study, with a focus on shame and disgust. TD completed neuropsychological and psychological assessments alongside an experimental task investigating processing of disgust and his living situation. Results highlighted executive dysfunction but understanding of living with the consequences of squalor was spared as was emotion based decision-making. Assessment indicated difficulties with olfactory processing and aspects of interoceptive awareness. TD showed poor awareness of his living conditions and a lack of shame. Disgust sensitivity was unimpaired. It is unclear if TD's difficulties were caused by psychological or neuropsychological impairments, although both likely play a part. Further research is required to understand processes underpinning DS, particularly disgust and shame.

Alexander's disease and the story of Louise.

We describe the rare condition known as Alexander's disease or Alexander's leukodystrophy, which is essentially a childhood dementia. We then present the case of Louise Davies (we are using Louise's real name with the permission and special request of her mother), a woman who was diagnosed with this disease at the age of 5 years and is still alive at the age of 38, making her the longest known survivor of this condition. Although now severely impaired, both physically and mentally, and able to do very little, she has lived far longer than expected. We present some neuropsychological results from her childhood before measuring her decline over the past four years. We conclude by considering whether or not the diagnosis was correct and why she has lived so long.

Does Modafinil improve the level of consciousness for people with a prolonged disorder of consciousness? a retrospective pilot study.

BACKGROUND AND AIM: Modafinil is best known as a sleep regulator among healthy individuals, but studies suggest that it reduces excessive daytime sleepiness in patients with brain injury. This retrospective pilot study evaluated the effectiveness of Modafinil for people with a prolonged disorder of consciousness and whether those with a traumatic brain injury did better than those with a non-traumatic brain injury. METHOD: Twenty four prolonged disorder of consciousness patients who were prescribed Modafinil, were assessed at least four times both before and during treatment. The Coma Recovery Scale-Revised was used to determine if patients had a disorder of consciousness and the Wessex Head Injury Matrix was used to monitor behavior during baseline and treatment periods. Patients with a traumatic brain injury (N = 12) were compared with those with non-traumatic brain injury (N = 12). A chi-square test with significance at 0.05 was used and when frequencies were below 5 a Fisher's Exact Test was used. RESULTS: Cognitive improvements were noted in domains of wakefulness, awareness, concentration, tracking and following commands. Significant differences were found for the whole group between baseline and Modafinil (x2 = 9.80; p = 0.002). Eleven of the 12 traumatic brain injury patients had higher Wessex Head Injury Matrix scores when on Modafinil (x2 = 8.33, p < 0.004). Six non-traumatic brain injury patients had higher scores with Modafinil, two had lower scores and four showed no change. There was no significant difference in the number of patients showing an increase compared to those showing a decrease (Fisher's exact test p = 0.29). CONCLUSION: Modafinil appears to be beneficial for enhancing cognition in prolonged disorder of consciousness patients. Traumatic brain injury patients benefited more than non-traumatic brain injury patients. Implications for Rehabilitation People with prolonged disorders of consciousness are those in coma, a vegetative state or a minimally conscious state. Sensorimotor and neuromodulations (pharmacological and brain stimulation) are the available treatment strategies to this group. Modafinil promotes attention, concentration and maintains wakefulness in a patient with narcolepsy, obstructive sleep apnea and shift work sleep disorders. In a relatively small sample, this retrospective pilot study shows the effectiveness of Modafinil in conjunction with good care, suitable medications and multidisciplinary rehabilitation in enhancing arousal in prolonged disorders of consciousness patients.

Seeing red: Relearning to read in a case of Balint's Syndrome.

BACKGROUND AND AIMS: Balint's Syndrome is a rare condition, often associated with hypoxic brain damage. The major characteristic is an inability to localise objects in space, another is simultanagnosia frequently resulting in reading difficulties. We present RN, a 37 year old woman whose major problem with reading was her inability to recognise individual letters correctly in either lower or upper case. We noted, however, that she was better if the letters were shown in red type. The aims were to determine if RN could relearn letters of the alphabet, investigate whether colour affected her ability to learn, and to explore more specifically whether the red type also helped her to read words. METHOD: Using a single case experimental ABA design, we first determined that the optimal font for RN was size 16. In the baseline (A) phase, we assessed her ability to read all lower and upper case letters of the alphabet in black ink. In the intervention (B) phase we used font size 16 in red ink and an errorless learning approach to teaching the letters. Sessions ran 5 times per week (20 minutes per session). The intervention was then applied to picture recognition and word reading with four sets of 10 words and corresponding pictures. RESULTS: A consistent difference was noted between initial baseline and intervention. Improvement carried over when we returned to baseline. CONCLUSION: Using red type and an errorless learning approach enabled RN to re-learn letters of the alphabet and read words she was previously unable to read. This did not however generalise to her everyday life.