Grazing herbivores reduce herbaceous biomass and fire activity across African savannas.

Fire and herbivory interact to alter ecosystems and carbon cycling. In savannas, herbivores can reduce fire activity by removing grass biomass, but the size of these effects and what regulates them remain uncertain. To examine grazing effects on fuels and fire regimes across African savannas, we combined data from herbivore exclosure experiments with remotely sensed data on fire activity and herbivore density. We show that, broadly across African savannas, grazing herbivores substantially reduce both herbaceous biomass and fire activity. The size of these effects was strongly associated with grazing herbivore densities, and surprisingly, was mostly consistent across different environments. A one-zebra increase in herbivore biomass density (~100 kg/km2 of metabolic biomass) resulted in a ~53 kg/ha reduction in standing herbaceous biomass and a ~0.43 percentage point reduction in burned area. Our results indicate that fire models can be improved by incorporating grazing effects on grass biomass.

Shining new light on mammalian diving physiology using wearable near-infrared spectroscopy.

Investigation of marine mammal dive-by-dive blood distribution and oxygenation has been limited by a lack of noninvasive technology for use in freely diving animals. Here, we developed a noninvasive near-infrared spectroscopy (NIRS) device to measure relative changes in blood volume and haemoglobin oxygenation continuously in the blubber and brain of voluntarily diving harbour seals. Our results show that seals routinely exhibit preparatory peripheral vasoconstriction accompanied by increased cerebral blood volume approximately 15 s before submersion. These anticipatory adjustments confirm that blood redistribution in seals is under some degree of cognitive control that precedes the mammalian dive response. Seals also routinely increase cerebral oxygenation at a consistent time during each dive, despite a lack of access to ambient air. We suggest that this frequent and reproducible reoxygenation pattern, without access to ambient air, is underpinned by previously unrecognised changes in cerebral drainage. The ability to track blood volume and oxygenation in different tissues using NIRS will facilitate a more accurate understanding of physiological plasticity in diving animals in an increasingly disturbed and exploited environment.

Metabolic heat loss in southern elephant seals (Mirounga leonina) differs with stage of moult and between habitats.

The moult in southern elephant seals (Mirounga leonina) represents an especially energetically demanding period during which seals must maintain high skin temperature to facilitate complete replacement of body fur and upper dermis. In this study, heat flux from the body surface was measured on 18 moulting southern elephant seals to estimate metabolic heat loss in three different habitats (beach, wallow and vegetation). Temperature data loggers were also deployed on 10 southern elephant seals to monitor skin surface temperature. On average, heat loss of animals on the beach was greater than in wallows or vegetation, and greater in wallows than in vegetation. Heat loss across all habitats during the moult equated to 1.8 x resting metabolic rate (RMR). The greatest heat loss of animals was recorded in the beach habitat during the late moult, that represented 2.3 x RMR. Mass loss was 3.6 ± 0.3 kg day-1, resulting in changes in body condition as the moult progressed. As body condition declined, skin surface temperature also decreased, suggesting that as animals approached the end of the moult blood flow to the skin surface was no longer required for hair growth.

Multiple-Pulse Sounds and Seals: Results of a Harbor Seal (Phoca vitulina) Telemetry Study During Wind Farm Construction.

Offshore construction and survey techniques can produce pulsed sounds with a high sound pressure level. In coastal waters, the areas in which they are produced are often also used by seals, potentially resulting in auditory damage or behavioral avoidance. Here, we describe a study on harbor seals during a wind farm installation off southeast England. The study used GPS/global system for mobile communication tags on 23 harbor seals that provided distribution and activity data; the closest range of individual seals to piling varied from 6.65 to 46.1 km. Furthermore, the maximum predicted received levels (RLs) at individual seals varied between 146.9 and 169.4 dB re 1 µPa peak to peak.

Plant community response to loss of large herbivores differs between North American and South African savanna grasslands.

Herbivory and fire shape plant community structure in grass-dominated ecosystems, but these disturbance regimes are being altered around the world. To assess the consequences of such alterations, we excluded large herbivores for seven years from mesic savanna grasslands sites burned at different frequencies in North America (Konza Prairie Biological Station, Kansas, USA) and South Africa (Kruger National Park). We hypothesized that the removal of a single grass-feeding herbivore from Konza would decrease plant community richness and shift community composition due to increased dominance by grasses. Similarly, we expected grass dominance to increase at Kruger when removing large herbivores, but because large herbivores are more diverse, targeting both grasses and forbs, at this study site, the changes due to herbivore removal would be muted. After seven years of large-herbivore exclusion, richness strongly decreased and community composition changed at Konza, whereas little change was evident at Kruger. We found that this divergence in response was largely due to differences in the traits and numbers of dominant grasses between the study sites rather than the predicted differences in herbivore assemblages. Thus, the diversity of large herbivores lost may be less important in determining plant community dynamics than the functional traits of the grasses that dominate mesic, disturbance-maintained savanna grasslands.

Loss of a large grazer impacts savanna grassland plant communities similarly in North America and South Africa.

Large herbivore grazing is a widespread disturbance in mesic savanna grasslands which increases herbaceous plant community richness and diversity. However, humans are modifying the impacts of grazing on these ecosystems by removing grazers. A more general understanding of how grazer loss will impact these ecosystems is hampered by differences in the diversity of large herbivore assemblages among savanna grasslands, which can affect the way that grazing influences plant communities. To avoid this we used two unique enclosures each containing a single, functionally similar large herbivore species. Specifically, we studied a bison (Bos bison) enclosure at Konza Prairie Biological Station, USA and an African buffalo (Syncerus caffer) enclosure in Kruger National Park, South Africa. Within these enclosures we erected exclosures in annually burned and unburned sites to determine how grazer loss would impact herbaceous plant communities, while controlling for potential fire-grazing interactions. At both sites, removal of the only grazer decreased grass and forb richness, evenness and diversity, over time. However, in Kruger these changes only occurred with burning. At both sites, changes in plant communities were driven by increased dominance with herbivore exclusion. At Konza, this was caused by increased abundance of one grass species, Andropogon gerardii, while at Kruger, three grasses, Themeda triandra, Panicum coloratum, and Digitaria eriantha increased in abundance.

Increasing frost risk associated with advanced citrus flowering dates in Kerman and Shiraz, Iran: 1960-2010.

Flowering dates and the timing of late season frost are both driven by local ambient temperatures. However, under climatic warming observed over the past century, it remains uncertain how such impacts affect frost risk associated with plant phenophase shifts. Any increase in frost frequency or severity has the potential to damage flowers and their resultant yields and, in more extreme cases, the survival of the plant. An accurate assessment of the relationship between the timing of last frost events and phenological shifts associated with warmer climate is thus imperative. We investigate spring advances in citrus flowering dates (orange, tangerine, sweet lemon, sour lemon and sour orange) for Kerman and Shiraz, Iran from 1960 to 2010. These cities have experienced increases in both T max and T min, advances in peak flowering dates and changes in last frost dates over the study period. Based on daily instrumental climate records, the last frost dates for each year are compared with the peak flowering dates. For both cities, the rate of last frost advance lags behind the phenological advance, thus increasing frost risk. Increased frost risk will likely have considerable direct impacts on crop yields and on the associated capacity to adapt, given future climatic uncertainty.

Psychological distress and PTSD among clinicians in Roma, Lesotho during the COVID-19 pandemic.

BACKGROUND:  Since 2020, the world has been battling the coronavirus disease 2019 (COVID-19) pandemic. The mortality and morbidity at the height of the pandemic sparked generalised fear and uncertainty about the future. Concerns were raised about the psychological impact of the pandemic on workers in healthcare systems globally. This study was conducted to establish the degree of psychological impact of the pandemic on frontline health workers in Lesotho. METHODS:  The study used a quantitative cross-sectional survey design. The Kessler psychological distress screening tool (K-10) and the post-traumatic stress disorder (PTSD) checklist for civilians (PCL-C) were administered to screen for psychological distress among clinical staff at St. Joseph's Hospital in Roma and its four Health Centres. Additional open- and closed-ended questions were added for context. Data were analysed using Fisher's exact tests, Pearson chi-square tests and correlation studies. RESULTS:  Of the 101 participants, 42 (41.6%) scored ≥ 24 on the K-10 scale (95% CI: 32.0% - 51.2%) indicating moderate to severe psychological distress and 32 (31.7%) scored ≥ 50 on the PCL-C checklist suggesting severe PTSD (95% CI: 24.5% - 42.9%). High scores on the K-10 were found more among men than women (17 [37.8%] vs. 4 [7.1%]; p ≤ 0.001). Post-traumatic stress disorder was more in the younger age group (p ≤ 0.03), in those reporting anxiety (p = 0.005) and those with more co-morbidities (p ≤ 0.001). CONCLUSION:  This study revealed the grave psychological impact of the COVID-19 pandemic on frontline clinical health workers in Lesotho.Contribution: These data will assist health leaders and policymakers to implement mental health support interventions for health workers in future.

Sink fast and swim harder! Round-trip cost-of-transport for buoyant divers.

Efficient locomotion between prey resources at depth and oxygen at the surface is crucial for breath-hold divers to maximize time spent in the foraging layer, and thereby net energy intake rates. The body density of divers, which changes with body condition, determines the apparent weight (buoyancy) of divers, which may affect round-trip cost-of-transport (COT) between the surface and depth. We evaluated alternative predictions from external-work and actuator-disc theory of how non-neutral buoyancy affects round-trip COT to depth, and the minimum COT speed for steady-state vertical transit. Not surprisingly, the models predict that one-way COT decreases (increases) when buoyancy aids (hinders) one-way transit. At extreme deviations from neutral buoyancy, gliding at terminal velocity is the minimum COT strategy in the direction aided by buoyancy. In the transit direction hindered by buoyancy, the external-work model predicted that minimum COT speeds would not change at greater deviations from neutral buoyancy, but minimum COT speeds were predicted to increase under the actuator disc model. As previously documented for grey seals, we found that vertical transit rates of 36 elephant seals increased in both directions as body density deviated from neutral buoyancy, indicating that actuator disc theory may more closely predict the power requirements of divers affected by gravity than an external work model. For both models, minor deviations from neutral buoyancy did not affect minimum COT speed or round-trip COT itself. However, at body-density extremes, both models predict that savings in the aided direction do not fully offset the increased COT imposed by the greater thrusting required in the hindered direction.

The role of self-efficacy and catastrophizing in explaining improvements in disability, pain and fatigue among patients with chronic widespread pain treated with physiotherapy: an exploratory analysis.

OBJECTIVES: Most research exploring the relationship between cognitive factors (catastrophizing and self-efficacy beliefs) and levels of pain, disability and fatigue in patients with chronic widespread pain has been performed in multidisciplinary environments. It is less clear whether these associations are valid in other clinical environments. This study therefore aimed to establish whether changes in cognitive factors were related to changes in pain, disability and fatigue among patients treated in a physiotherapy-led symptom management programme. DESIGN: A longitudinal pre-post treatment study. Regression analyses were performed with change in pain, disability, physical and mental fatigue as the dependent measures. Demographics, change in pain and fatigue (when not dependent variables) and cognitive factors were entered as independent variables. ß values were calculated for the final model. SETTING: Two out-patient physiotherapy departments in Manchester, UK. PARTICIPANTS: Fifty patients with persistent widespread pain. INTERVENTION: A physiotherapist-led symptom management programme. MAIN OUTCOME MEASURES: Disability (Fibromyalgia Impact Questionnaire), Pain (Numeric Pain Rating Scale and Fatigue (Chalder Fatigue Scale) RESULTS: Significant changes in disability, fatigue and cognitive factors were observed after treatment. Changes in self-efficacy beliefs (ß=-0.38, P<0.05) and catastrophizing (ß=0.41, P<0.05) were significantly related to reductions in disability. There was no significant relationship between change in the cognitive variables and change in pain or fatigue. CONCLUSIONS: Self-efficacy beliefs and catastrophizing were important determinants of change in disability, but not pain or fatigue among patients with chronic widespread pain attending physiotherapy. Cognitively-informed physiotherapy appeared to be effective in reducing disability and fatigue and modifying cognitive factors. Such interventions may offer an effective treatment option for patients with chronic widespread pain and future randomised controlled trials are required to fully assess this.

Integrating herbivore assemblages and woody plant cover in an African savanna to reveal how herbivores respond to ecosystem management.

African savannas are experiencing anthropogenically-induced stressors that are accelerating the increase of woody vegetation cover. To combat this, land managers frequently implement large-scale clearing of trees, which can have a cascading influence on mammalian herbivores. Studies rarely focus on how differences in woody cover influence the herbivore assemblage, making it difficult to assess how aggressive measures, or the lack of management, to counteract increasing woody cover affect the local composition and biodiversity of herbivores. We address this knowledge gap by applying a model-based clustering approach to field observations from MalaMala Game Reserve, South Africa to identify multiple herbivore-vegetation 'configurations,' defined as unique sets of herbivore assemblages (i.e., groups of herbivores) associated with differing woody plant covers. Our approach delineated how tree-clearing influences the distribution and abundance of the herbivore community in relation to surrounding savanna areas, which represent a natural mosaic of varying woody cover. Regardless of season, both intensively managed areas cleared of trees and unmanaged areas with high tree cover contained configurations that had depauperate assemblages of herbivores (low species richness, low abundance). By contrast, habitats with intermediate cover of woody vegetation had much higher richness and abundance. These results have substantial implications for managing African savannas in a rapidly changing climate.

Atypical beta power fluctuation while listening to an isochronous sequence in dyslexia.

OBJECTIVE: Developmental dyslexia is a reading disorder that features difficulties in perceiving and tracking rhythmic regularities in auditory streams, such as speech and music. Studies on typical healthy participants have shown that power fluctuations of neural oscillations in beta band (15-25 Hz) reflect an essential mechanism for tracking rhythm or entrainment and relate to predictive timing and attentional processes. Here we investigated whether adults with dyslexia have atypical beta power fluctuation. METHODS: The electroencephalographic activities of individuals with dyslexia (n = 13) and typical control participants (n = 13) were measured while they passively listened to an isochronous tone sequence (2 Hz presentation rate). The time-frequency neural activities generated from auditory cortices were analyzed. RESULTS: The phase of beta power fluctuation at the 2 Hz stimulus presentation rate differed and appeared opposite between individuals with dyslexia and controls. CONCLUSIONS: Atypical beta power fluctuation might reflect deficits in perceiving and tracking auditory rhythm in dyslexia. SIGNIFICANCE: These findings extend our understanding of atypical neural activities for tracking rhythm in dyslexia and could inspire novel methods to objectively measure the benefits of training, and predict potential benefit of auditory rhythmic rehabilitation programs on an individual basis.

Increased Metabolic Rate of Hauled-Out Harbor Seals (Phoca vitulina) during the Molt.

AbstractHarbor seals (Phoca vitulina) live in cold temperate or polar seas and molt annually, renewing their fur over a period of approximately 4 wk. Epidermal processes at this time require a warm skin; therefore, to avoid an excessive energy cost at sea during the molt, harbor seals and many other pinnipeds increase the proportion of time they are hauled out on land. We predicted that metabolic rate during haul-out would be greater during the molt to sustain an elevated skin temperature in order to optimize skin and hair growth. To examine this, we measured post-haul-out oxygen consumption (V˙O2) in captive harbor seals during molt and postmolt periods. We recorded greater V˙O2 of seals while they were molting than when the molt was complete. Post-haul-out V˙O2 increased faster and reached a greater maximum during the first 40 min. Thereafter, V˙O2 decreased but still remained greater, suggesting that while metabolic rate was relatively high throughout haul-outs, it was most pronounced in the first 40 min. Air temperature, estimated heat increment of feeding, and mass also explained 15.5% of V˙O2 variation over 180 min after haul-out, suggesting that the environment, feeding state, and body size influenced the metabolic rate of individual animals. These results show that molting seals have greater metabolic rates when hauled out, especially during the early stages of the haul-out period. As a consequence, human disturbance that changes the haul-out behavior of molting seals will increase their energy costs and potentially extend the duration of the molt.

Cognitive factors are associated with disability and pain, but not fatigue among physiotherapy attendees with persistent pain and fatigue.

OBJECTIVES: Most research exploring the relationship between cognitive factors and pain, disability and fatigue in patients with persistent pain/fatigue has been performed in multi disciplinary environments. It is unclear whether these associations are consistent in other contexts. This study therefore aimed to establish the relationships between these factors in patients with persistent pain/fatigue referred for physiotherapy treatment. DESIGN: Cross-sectional observational study assessing the association between cognitive factors (self-efficacy and catastrophizing) and levels of pain, disability, mental fatigue and physical fatigue in patients with persistent pain/fatigue disorders. Data were analysed using regression analyses. SETTING: Two out-patient physiotherapy departments, Manchester, UK. PARTICIPANTS: 166 patients with persistent pain and fatigue disorders chronic widespread pain, fibromyalgia and chronic fatigue syndrome/myalgic encephalopathy). MAIN OUTCOME MEASURES: Disability was assessed using the Fibromyalgia Impact Questionnaire, whilst mental and physical fatigue were assessed with the sub-scales of the Chalder Fatigue Scale. Pain intensity was measured with a Numeric Pain Rating Scale, self-efficacy with the Chronic Pain Self-efficacy Questionnaire and catastrophizing with the Pain Catastrophizing Scale. RESULTS: Cognitive factors were significantly associated with pain (self-efficacy beliefs ß=-0.30, P<0.05; catastrophizing ß=0.24, P<0.05) and disability (self-efficacy beliefs ß=-0.62, P<0.05), but not fatigue. CONCLUSIONS: Similar associations were observed in patients referred to physiotherapy as to those observed in patients treated in multi disciplinary clinical environments. Self-efficacy beliefs appear to be particularly strong determinants of disability, but exert a lesser influence over pain or fatigue. Targeting self-efficacy may be an effective method to reduce disability in patients with persistent pain and fatigue disorders.

Electronic-prescribing tools improve N-acetylcysteine prescription accuracy and timeliness for patients who present following a paracetamol overdose: A digital innovation quality-improvement project.

OBJECTIVES: Prescription error rates and delays in treatment provision are high for N-acetylcysteine (NAC) when prescribed for paracetamol overdose (POD). We hypothesised that an electronic tool which proposed the complete NAC regimen would reduce prescription errors and improve the timeliness of NAC provision. Error rates and delays in the provision of NAC were assessed following POD, before and after the implementation of an electronic prescribing tool. METHODS: The NAC electronic prescribing tool proposed the three NAC infusions (dosed for weight) following entry of the patient's weight. All NAC prescriptions were reviewed during a three-month period prior to and after the tool's implementation. Error rates were divided into dose, infusion volume or infusion rate. Delays in NAC provision were identified using national Emergency Medicine guidelines. RESULTS: 108 NAC prescriptions were analysed for all adult patients admitted to the emergency department of a secondary care hospital in the UK between July-September 2017 and August-October 2018, respectively. There were no differences in the demographics of patients or the seniority of the prescribing clinician before or after the introduction of the electronic tool. The electronic prescribing tool was associated with a decrease in prescribing errors (25% to 0%, p < 0.0071) and an increase in the provision of NAC within recommended times (11.1% to 47.4%, p = 0.029). CONCLUSIONS: An electronic prescribing tool improved prescription errors and the timeliness of NAC provision following POD. Further studies will determine the effect of this on length of stay and the benefit of wider implementation in other secondary care hospitals.

Regular rhythmic primes boost P600 in grammatical error processing in dyslexic adults and matched controls.

Regular musical rhythms orient attention over time and facilitate processing. Previous research has shown that regular rhythmic stimulation benefits subsequent syntax processing in children with dyslexia and specific language impairment. The present EEG study examined the influence of a rhythmic musical prime on the P600 late evoked-potential, associated with grammatical error detection for dyslexic adults and matched controls. Participants listened to regular or irregular rhythmic prime sequences followed by grammatically correct and incorrect sentences. They were required to perform grammaticality judgments for each auditorily presented sentence while EEG was recorded. In addition, tasks on syntax violation detection as well as rhythm perception and production were administered. For both participant groups, ungrammatical sentences evoked a P600 in comparison to grammatical sentences and its mean amplitude was larger after regular than irregular primes. Peak analyses of the P600 difference wave confirmed larger peak amplitudes after regular primes for both groups. They also revealed overall a later peak for dyslexic participants, particularly at posterior sites, compared to controls. Results extend rhythmic priming effects on language processing to underlying electrophysiological correlates of morpho-syntactic violation detection in dyslexic adults and matched controls. These findings are interpreted in the theoretical framework of the Dynamic Attending Theory (Jones, 1976, 2019) and the Temporal Sampling Framework for developmental disorders (Goswami, 2011).

Rapid recovery of ecosystem function following extreme drought in a South African savanna grassland.

Climatic extremes, such as severe drought, are expected to increase in frequency and magnitude with climate change. Thus, identifying mechanisms of resilience is critical to predicting the vulnerability of ecosystems. An exceptional drought (

The processes underpinning reductions in disability among people with chronic neck pain. A preliminary comparison between two distinct types of physiotherapy intervention.

PURPOSE: To establish whether different processes underpin changes in disability in people with neck pain who underwent two types of active physiotherapy intervention. MATERIALS AND METHODS: This study was a sub-analysis of a randomized controlled trial assessing whether the addition of Interactive Behavioral Modification Therapy (a cognitively informed physiotherapy treatment) to a Progressive Neck Exercise Program improved outcome in patients with chronic neck pain. Regression analyses were performed to determine the extent to which demographics, changes in pain, and changes in certain cognitive factors were related to changes in disability. RESULTS: In the progressive neck exercise group, changes in levels of pain intensity were the only factor significantly related to change in disability, explaining 33% of the variance. In the interactive behavioral modification therapy group, changes in pain intensity, and catastrophizing together explained 54% of the variance in change in disability. Only changes in catastrophizing displayed a significant ß value in the final model. CONCLUSIONS: Different processes appear to underpin changes in disability in patients undergoing cognitively informed physiotherapy to those undergoing a primarily exercise-based approach. Implications for rehabilitation Certain cognitive factors are known to be related to levels of disability in patients with chronic neck pain Specifically targeting these factors results in more patients making a clinically meaningful reduction in disability Different processes appear to underpin reductions in disability when people with neck pain are treated with cognitively informed physiotherapy to when treated with exercise alone, which may account for why more patients improve when treated in this manner. Reductions in catastrophizing appear to be particularly important and efforts should be made to assess and treat catastrophic thoughts in people with chronic neck pain.

Change in dominance determines herbivore effects on plant biodiversity.

Herbivores alter plant biodiversity (species richness) in many of the world's ecosystems, but the magnitude and the direction of herbivore effects on biodiversity vary widely within and among ecosystems. One current theory predicts that herbivores enhance plant biodiversity at high productivity but have the opposite effect at low productivity. Yet, empirical support for the importance of site productivity as a mediator of these herbivore impacts is equivocal. Here, we synthesize data from 252 large-herbivore exclusion studies, spanning a 20-fold range in site productivity, to test an alternative hypothesis-that herbivore-induced changes in the competitive environment determine the response of plant biodiversity to herbivory irrespective of productivity. Under this hypothesis, when herbivores reduce the abundance (biomass, cover) of dominant species (for example, because the dominant plant is palatable), additional resources become available to support new species, thereby increasing biodiversity. By contrast, if herbivores promote high dominance by increasing the abundance of herbivory-resistant, unpalatable species, then resource availability for other species decreases reducing biodiversity. We show that herbivore-induced change in dominance, independent of site productivity or precipitation (a proxy for productivity), is the best predictor of herbivore effects on biodiversity in grassland and savannah sites. Given that most herbaceous ecosystems are dominated by one or a few species, altering the competitive environment via herbivores or by other means may be an effective strategy for conserving biodiversity in grasslands and savannahs globally.