An exploration of the crystallographic theory of the relatively novel method of Microcrystal Electron Diffraction (MicroED), via comparison to X-ray crystallography at the theoretical and practical level as it applies to biological macromolecules. We then attempt to outline the limitations and challenges that the technique currently faces in structural biology, and suggest future areas of study that may improve and optimize the technique.
An examination of community structure and associative niche habitats on the Coleoptera of Dawlish Warren were carried out. The aim of this study was to better understand coleopteran communities frequently ignored in coastal habitats that are at significant risk of becoming endangered due to conflicting coastal human activities and rising sea levels resulting in a coastal squeeze. Here, we hypothesise that the shoreline Coleoptera are an extension of neighbouring coleopteran communities and so will find little difference in community structure. Two techniques were used: pitfall trapping and shoreline sampling. A dry pitfall trap was designed to facilitate live trapping of insects and that guarded against the killing of vertebrates such as sand lizards. Shoreline sampling using a quadrat along a transect was carried out to establish whether this approach could be used as an alternative to pitfall trapping to assess the beetle fauna of the site. Beetles were captured from June until September 2017. A total of 56 species across 15 families were captured with 20 species a first recording for Dawlish Warren. Pitfall traps in the dune system produced 50 species while the shoreline sampling yielded just 13 species. The community structure was observably different between the shoreline and dune system in addition to the disparity in numbers. It was concluded that driftwood and seaweed were important attributes to shoreline coleopteran communities along with a lower pebble presence. Not all of the species in the dunes took to the air to disperse and in doing so exposed themselves to the possibility of becoming stranded in the sea. This point and the fact that a number of beetles captured were shoreline specialists meant that shoreline sampling could not serve as an alternative to pitfall trapping to survey for beetles on this site.
Hibernation is a natural process in many mammals to maximise survival during extreme environmental conditions. It is characterised by profound physiological changes such as reductions in metabolic rates and core body temperature for prolonged periods of time of up to 9 months. The ability of hibernating animals to recover from hibernation with no obvious signs of organ injury makes them excellent models for the clinical application of this natural protective mechanism, which has generated great interest in medical research. Recent studies have shed more light on the genetic and molecular basis of hibernation and several chemical compounds have been demonstrated to play significant roles in the regulation of hibernation, with an increasing focus on investigating their potential clinical applications in organ preservation and even development of cryonics techniques. In this review, I will present recent progress made in understanding the mechanism of hibernation and highlight evidence for hibernation induction in non-hibernating mammals using chemical compounds; finally, I will discuss the potential for combining genetic techniques to induce metabolic suppression for therapeutic purposes.
Manganese (Mn) is an essential metal involved in several cellular metabolic pathways including DNA synthesis, sugar metabolism and protein modification. The majority of Mn is obtained through the diet in food products such as nuts, whole grains and leafy greens. Abundant in most diets, Mn deficiency is rare while excess exposure in the occupational environment leads to cytotoxic levels. Labour workers commonly inhale Mn in settings like welding and mining. Metal inhalation bypasses many of the body’s homeostatic pathways leading to accumulation in the brain. Physiologically, the presence of Mn in Mn-sensitive brain regions, such as the globus pallidus, has been linked to neurodegeneration and induction of a Parkinsonian-like syndrome known as manganism. Mn homeostasis is therefore critical for brain health. The liver controls the redistribution of excess Mn to specific tissues/organs and hepatobiliary clearance. Mutations in Mn transporters, however, compromises homeostasis causing hepatic damage and surplus body Mn. Understanding Mn toxicity in hepatocytes is crucial for developing new medicines that prevent blood Mn build-up. To understand the molecular changes attributed to excess hepatic Mn, we sought to determine changes in hepatocyte viability under Mn hepatotoxicity. For these experiments, polarized hepatocytoma WIF-B cells were grown for 12–14 days to achieve maximal polarity. Immunocytochemistry, Western blot and MTT viability assays helped characterize Mn’s effect on the Golgi. We found that WIF-B cell viability was maintained during 4 h exposures of up to 100 μM Mn. Under these conditions, we identified no change at the cis-Golgi but levels of the trans-Golgi marker TGN38 fell in a dose-dependent manner. Immunofluorescence (IF) images confirmed that Mn-induced TGN38 loss, while the cis-Golgi marker GM130 remained unaffected. Treatment with the lysosomal inhibitor Bafilomycin A1 for 16 h prevented degradation of TGN38 when cells were exposed to Mn for 4 h and increased its co-localization with the late endosomal marker mannose-6-phosphate receptor (M6PR). Our results suggest disrupting Mn homeostasis negatively affects the integrity of the Golgi apparatus, altering normal Mn trafficking in WIF-B cells. Understanding how Mn-induced changes in the Golgi architecture affect toxicity is key to developing therapeutic treatments for Mn toxicity.
Cleome ciliata Schum. & Thonn. of the family Cleomaceae, is an annual herb. Phytochemical screening was carried out and the in vitro antimicrobial activities of leaf, stem and root extracts of C. ciliata were assessed using standard techniques. Duncan’s multiple range test was used to assess the significance of the results. The highest concentration of flavonoids (1.83 ± 0.04 mg/100 g), phenols (0.65 ± 0.00 mg/100 g) and terpenoids (1.93 ± 0.05 mg/100 g) was found in the leaf, stem and root respectively. Extracts of all the plant parts exhibited inhibitory activity against all test bacterial and fungal pathogens that are dose-dependent while the antagonistic effects of the leaf and root extracts were higher. The leaf extract showed the highest inhibition of Klebsiella pneumoniae, Streptococcus pneumoniae, Staphylococcus aureus, Salmonella typhi, Pseudomonas aeruginosa, Rhizopus stolonifer and Fusarium oxysporum; the root extract showed the highest inhibitory activity against K. pneumoniae and Penicillium chrysogenum while the three extracts were least effective against Escherichia coli, Shigella sonnei and Aspergillus niger. The study demonstrated that C. ciliata contains phytochemicals with antimicrobial properties and hence, its potential in antibacterial and antifungal drug development.
Many animals benefit from aggregating due to the anti-predator effects associated with living in groups. Hermit crabs are known to form groups, or ‘clusters’, which may occur at sites of high shell availability. Clustering may also have anti-predator benefits, if individuals in larger clusters able to spend less time engaging in defensive behaviours such as hiding in their shells. Here, we test the hypothesis that crabs in larger clusters will emerge faster from their shells after an elicited startle response in the European hermit crab (Pagurus bernhardus). We found that individuals were generally consistent in their emergence times across group sizes (displaying ‘personality’ in relation to emergence time), but that group size influenced emergence time in P. bernhardus. In contrast to the hypothesis, crabs in larger clusters had longer emergence times relative to their own emergence times in smaller clusters. Suggested explanations for this effect include intra-specific competition for the gastropod shells that hermit crabs inhabit, as well as the possible release of chemical cues by crabs in larger clusters.
Industrialization processes are prone to produce various forms of waste which can be utilized to produce silage. These wastes can be treated by using lactic acid bacteria (LAB), which are known to be potential enzyme producers. Seven strains of LAB were isolated from traditional fermented food, 'tapai pulut', 'tempeh', 'tempoyak' and 'fu yu' and were screened for amylase, cellulase and protease production in order to select for strains that could potentially be used industrially in silage production. All seven LAB isolates exhibited high protease production, and two of them also exhibited high amylase and cellulase production. The two isolates exhibiting high amylase and cellulase production were selected and identified as Pediococcus acidilactici FY2 and Enterococcus durans FY3 via biochemical profiling (API 50 CHL) and 16 s rDNA sequencing. E. durans was found to have the highest amylase (Vmax: 5.51 μmol/mL/min; Km: 0.300 g/100 mL) and cellulase (Vmax: 3.50 μmol/mL/min; Km: 0.006 g/100 mL) production, while exhibiting strong protease production (Vmax: 0.51 μmol/mL/min; Km: −0.287 g/100 mL). P. acidilactici was found to have strong amylase (Vmax: 4.43 μmol/mL/min; Km: 0.433 g/100 mL) and cellulase (Vmax: 2.66 μmol/mL/min; Km: 0.002 g/100 mL) production while exhibiting the highest protease production (Vmax: 2.14 μmol/mL/min; Km: −0.348 g/100 mL). These results suggest that E. durans is a better candidate for future industrial application as overall it has a higher enzyme reaction velocity when compared to P. acidilactici. Further studies should be carried out to confirm the Km value for protease production, to purify and characterize all three enzymes produced and to optimize the growth conditions of E. durans.
As the population of the world grows, so does the need for sustainable food. Insect farming and consumption can help ease the burden of supply from other more conventional food sources. This article investigates the prevalence of allergic reactions caused by consuming edible insects. The investigation was conducted in the North-Eastern or the Isan region of Thailand, in an area where insect consumption or entomophagy is a common practice. Information concerning insect consumption and allergic reactions were gathered from multiple sources in four locations: Nongki, Nang Rong, Nong Bun Mak and Nakhon Ratchasima. The survey included questions about eating habits in relation to insects, other known food allergies and presented a list of symptoms the participants may have experienced. The results from 2500 respondents were surprising in that the prevalence of allergic reactions caused by consuming edible insects was much higher than expected. In the Isan region approximately 7.4% of people experienced an adverse reaction indicative of an edible-insect allergy and 14.7% of people experienced multiple adverse reactions indicative of an edible-insect allergy. Furthermore, approximately 46.2% of people that already suffer from a known food-based allergy also experienced symptoms indicative of an allergic reaction after insect consumption. The most common symptoms appear to be gastro-intestinal (diarrhoea and vomiting). In conclusion, the allergy aspect of entomophagy is a serious issue and has the potential to adversely affect the future of entomophagy, especially in introducing the concept to western cultures. Although preliminary in its findings, this article hopes to ignite further research into the topic in order to fully understand the implications and role that edible insects can have on the immune system.
Native to Southern Africa, Lagarosiphon major is a submerged macrophyte that is recognized as a problematic, invasive non-native species in many countries including the UK. It is widely sold and promoted through the aquarium and water garden industry as an ‘efficient oxygenator’ for freshwater systems, irrespective of the absence of evidence to support this statement and evidence of its adverse ecological and economic impacts. A key concern, relating to its rapid growth rate and high fresh weight density, is that L. major can impose self-shading and limitation of photosynthetic and respiratory activity, causing it to consume more oxygen than it produces. Low dissolved oxygen (DO) conditions typify diminished water quality and seriously limit oxygen-dependent organisms. We measured over several months the DO, fresh weight and associated pond life abundances of L. major and a comparable UK-native macrophyte, Ceratophyllum demersum, established in small-pond conditions to determine which species best maintained a healthy freshwater environment. Both the time from establishment and species had significant effects on DO concentrations and pond life abundance; L. major produced the least amount of oxygen over time and had significantly less associated pond life compared to the native plant. L. major also increased significantly in overall fresh weight compared to C. demersum, indicating the higher invasive ability of the non-native species. In conclusion, our results suggest that L. major is not as good an oxygenator as C. demersum and that this native species should be promoted through the aquarium and water garden trades as an efficient oxygenator that improves water quality and habitat conditions over time.
Reference ranges (RRs) are not produced for different subsets of the population, other than for gender. This study aimed to explore the impact of generalised RRs on diagnosis thus proving the necessity for new RRs taking into account different ethnicities (hispanic, white, black and Asian). This impact was explored by direct comparisons of RRs produced for different ethnicities in which significant differences would provide evidence for possible misdiagnosis. This was achieved by creating RRs from the National Health and Nutrition Examination Survey, a programme of studies assessing the health and nutritional status of children and adults within USA. The 2.5th and 97.5th percentiles from the 2013–2014 data was calculated after those deemed unhealthy were removed via a set of extensive parameters. Having bootstrapped the data 30 times, a Kruskal–Wallis statistical test was performed followed by a Mann–Whitney post hoc. Nearly all male lower and upper limits were found to be significantly different to each other, apart from the upper limits of hispanic to both white and black, and white to black. Female results showed almost an equal amount of significant and non-significant differences. Those which were significantly different were the upper and lower limits of all the ethnicities to Black, alongside the lower limits of White to Asian. The results of this study suggest that a proportion of misdiagnosis could be avoided if separate RRs were produced, at least for different ethnicities.
High-throughput screening (HTS) has been firmly rooted at the heart of many drug discovery programs over the past few decades, having provided a starting point for the development of many of the drugs on the market. However, this technique is often accompanied by high-attrition rates and has proven to be unsuccessful at developing therapeutics against more non-conventional targets such as protein–protein interactions (PPIs). Fragment-based drug discovery (FBDD) offers an alternative approach and is steadily being taken up by the industry to tackle the high-attrition rate associated with many chemical leads developed by HTS. FBDD takes a structure-guided approach and uses a small chemical library of fragments during the initial screening process, to identify weakly binding ligands with the potential for therapeutic development. This review aims to summarise the challenges with screening in FBDD and the key biophysical screening techniques used for identification of weakly interacting ligands.
Habitat fragmentation and road mortalities are major contributors towards declines in amphibian populations. This has seen the introduction of culverts, passages that run under roads and provide safe passage for amphibians. Research investigating the effects of rainfall upon amphibian culvert use is limited. This study, conducted at Frankfield Loch in Glasgow, assesses how time elapsed since rainfall influences migration behaviour and the use of culverts across four different species; common toads (Bufo bufo), common frogs (Rana temporaria and newts, a group composed of smooth newts (Lissotriton vulgaris) and palmate newts (Lissotriton helveticus). Analysis of images taken by a custom made, time lapse camera found that significantly fewer common toads (r = 0.148, n = 468, p = 0.001) and common frogs (r = −0.175, n = 106, p = 0.037) used the culvert as time since rainfall increased. This may have been caused by the culvert not maintaining wet enough conditions for amphibians. The study also found that more newts (r = 0.272, n = 92, p = 0.004) and common toads (r = 0.531, n = 19, p = 0.010) were using the culvert to move away from Frankfield Loch as time since rainfall increased. An increase in juvenile newts was also observed as time since rainfall increased (r = 0.214, n = 92, p = 0.020). This may have been caused by a decrease in barometric pressure, which follows a decrease in rainfall, acting as a cue for migration and juvenile dispersal. The study recommends careful consideration of the design of each culvert, incorporating species-specific preferences and the requirements of juveniles. The study also suggests that where possible the culvert should be designed to hold water for longer.
Deprivation and socioeconomic status are associated with cardiovascular diseases. The aim of this study is to describe a relationship between socioeconomic deprivation and coronary heart disease (CHD) mortality. This study used publicly available data for English Indices of Multiple Deprivation (IMD) and CHD mortality rate. IMD data is a ranked score based on seven factors related to socioeconomic status. The average IMD rank and the average CHD mortality rate were collected from the Office of National Statistics website for each Clinical Commissioning Group (CCG) in UK. To investigate the relationship between IMD score and CHD mortality a linear regression was fitted using logged CHD data, because the spread of the CHD data was largest for higher values of IMD. This achieved a more symmetrical distribution of the data. The results from the regression model were retransformed to values representing the original CHD data. Analysis was performed using data from 209 CCGs. CHD mortality rate for the lowest IMD ranked CCG is 27.6 and for the highest 97.4. Using the log-CHD values, the linear regression model revealed that for a one-point increase in IMD rank score, CHD mortality rate increases by 1.03 on average (95% CI 1.02–1.03; P < 0.001). These data show that areas with higher deprivation had higher rates of mortality from CHD. These findings are supported by previous research, which emphasize the important relationship between socioeconomic status and public health crises.
Preliminary phytochemical screening was carried out and in vitro antimicrobial activities of leaves and stem of Mimosa invisa Mart. against some clinical pathogens were tested using standard techniques. Significance was measured using Duncan’s multiple range test. The inhibitory actions of the leaf and stem extracts increased with concentration. The rates of inhibition of the two extracts were low and high against Salmonella typhi and Aspergillus flavus respectively. The phytochemicals present in the plant parts had antimicrobial properties and reveal that M. invisa may have potential in pharmaceutical applications.
The development of efficacious treatments targeting Alzheimer’s disease (AD) aetiology has been proved an extensive, time-consuming task. Currently prescribed therapies, primarily acetylcholinesterase inhibitors such as donepezil and the NMDA-receptor antagonist memantine, concentrate on the improvement of symptoms such as cognitive decline and memory loss, however, do not address the underlying pathology of the condition. More recently, efforts have focused on developing drugs that target the hallmarks of AD, amyloid-β (Aβ) plaques and hyperphosphorylated tau tangles. Many clinical trials focusing on the removal of these proteins are presently ongoing, primarily exploring immunotherapeutic avenues such as the antibody aducanumab (targeting Aβ) and the vaccine AADvac-1 (targeting tau). However, the incomplete understanding of AD progression presents a challenge, and further studies focusing on the development of the disease are essential to the expansion of novel, efficient therapeutic routes.
The function of sleep is one of the enduring mysteries of modern neuroscience. Despite years of concerted research, it is still unclear why all known animals undergo a regular period of unconsciousness and what function this fulfils that simply cannot be performed during wakefulness. Key to identifying this function will be an understanding of the sleep homeostat. This internal bookkeeper measures the need for sleep that accumulates during wakefulness and dissipates during sleep. It therefore directly measures the processes that require sleep. This essay presents evidence that the sleep homeostat in Drosophila induces sleep through the activation of a group of 24 neurons projecting to the dorsal fan-shaped body (dFB) and identifies several sources of input to these effector neurons. I propose that this discovery allows a crucial reframing of the mystery of sleep as a molecular question and suggest experiments by which the dFB neurons can be used to evaluate existing theories of sleep. While current evidence is insufficient to support any one particular theory, this essay argues that future work investigating how the dFB is activated will lead to an understanding of the processes that require sleep and, thus, provide a window on the vital function of sleep.
Transcription factors (TFs), such as Snail, Slug and Twist, control the down-regulation of cell–cell adhesion molecule E-cadherin in ovarian cancer. Low E-cadherin aids tumour cells in undergoing epithelial–mesenchymal transition (EMT) to motile morphology, disseminating to other organs. High TF levels have also correlated with chemoresistance and poor prognosis. This review aims to discern mechanisms of E-cadherin reduction by TFs and identifies hypoxia-inducible factor 1α (HIF1α) as an upstream regulator in hypoxic conditions. Association with chemoresistance is investigated, and whether its reversal is possible. Snail was found to bind more strongly to the E-cadherin promoter than Slug; it was suggested that Snail maintained EMT whilst Slug induced it. The use of differential zinc fingers by Snail and Slug to bind to the E-cadherin promoter supported this. HIF1α was shown to lie upstream of all three TFs and protein degradation or post-transcriptional regulation using miR-548c may regulate of Twist downstream. Further study into this is needed. High Snail expression correlated with cisplatin resistance, with knockdown of Snail reversing it. The same may be true for Twist and Slug, though some studies conflicted this. These findings show promising potential of TFs and HIF1α as therapeutic targets for EMT prevention and even chemoresistance reversal.
Despite biology being 'The study of living organisms' (Proffitt, 2017), there is no consensus between biologists on the definition of life (Bedau, 2010). Defining life has challenged and divided biologists and philosophers alike ever since Aristotle proposed the first definition. Emerging fields like synthetic biology and exobiology have rekindled attempts at establishing a definition of life for practical purposes. The question presents many challenges with each attempt thus far leading to unintended implications and strong counterexamples. It is an inherently multidisciplinary challenge with each approach giving wildly varying and often irreconcilable definitions. The given definitions of life are numerous with over 300 definitions published in books and journals. The unique characteristics of the mimivirus, discovered in 2003, and later giant viruses, rekindled the discussion in defining life, indicating other complications in a definition.
Mangroves are increasingly being recognised for the important ecosystem services they provide, including carbon fixation, shoreline protection and fisheries habitats. In addition, they provide typical forest goods such as timber and firewood; harvesting these can cause forest degradation and loss. In Kenya, a large proportion of the rural population cook using firewood on traditional, inefficient three-stone fires. Although harvesting mangrove wood is illegal, the high poverty rate, absence of alternative fuels and lack of law enforcement mean it is likely to remain widespread, with consequent pressure on the forests. The use of three-stone fires has been associated with high levels of indoor air pollution, causing adverse health impacts. The current project aimed to determine a baseline of wood usage and health burden caused by indoor air pollution at a mangrove dependent community in Gazi Bay, southern Kenya. Basic information about fuel usage and perceived health problems related to indoor air pollution was collected using a questionnaire. Wood usage patterns were recorded for 28 days to establish the average daily wood consumption and main species used. Passive diffusion tubes were used to assess CO concentrations over 24 hours. Particulate pollution for the size fraction PM2.5 was measured during cooking using a DustTrak aerosol monitor. Mean daily per capita wood consumption was 1.2 kg although this varied significantly depending on household size, with larger households using less per capita wood. The mangrove Rhizophora mucronata made up 10% of wood used and people spent, on average, 22 hours per month collecting wood. The mean 24-hour CO concentration was 5.9ppm. The average level of PM2.5 during cooking was 10 mg/m3 respectively. Chronic exposure at those levels is expected to cause significant health impacts of the kinds indicated by symptoms reported from the questionnaires. Improved cookstove introduction in Gazi is recommended as feasible as participants showed not only interest in improved cookstoves and awareness of the health implications from indoor air pollution, but also were willing to invest financially in improved cookstoves.
