Period Of Days Research Articles

GDNF to the rescue: GDNF delivery effects on motor neurons and nerves, and muscle re-innervation after peripheral nerve injuries.

Peripheral nerve injuries commonly occur due to trauma, like a traffic accident. Peripheral nerves get severed, causing motor neuron death and potential muscle atrophy. The current golden standard to treat peripheral nerve lesions, especially lesions with large (≥ 3 cm) nerve gaps, is the use of a nerve autograft or reimplantation in cases where nerve root avulsions occur. If not tended early, degeneration of motor neurons and loss of axon regeneration can occur, leading to loss of function. Although surgical procedures exist, patients often do not fully recover, and quality of life deteriorates. Peripheral nerves have limited regeneration, and it is usually mediated by Schwann cells and neurotrophic factors, like glial cell line-derived neurotrophic factor, as seen in Wallerian degeneration. Glial cell line-derived neurotrophic factor is a neurotrophic factor known to promote motor neuron survival and neurite outgrowth. Glial cell line-derived neurotrophic factor is upregulated in different forms of nerve injuries like axotomy, sciatic nerve crush, and compression, thus creating great interest to explore this protein as a potential treatment for peripheral nerve injuries. Exogenous glial cell line-derived neurotrophic factor has shown positive effects in regeneration and functional recovery when applied in experimental models of peripheral nerve injuries. In this review, we discuss the mechanism of repair provided by Schwann cells and upregulation of glial cell line-derived neurotrophic factor, the latest findings on the effects of glial cell line-derived neurotrophic factor in different types of peripheral nerve injuries, delivery systems, and complementary treatments (electrical muscle stimulation and exercise). Understanding and overcoming the challenges of proper timing and glial cell line-derived neurotrophic factor delivery is paramount to creating novel treatments to tend to peripheral nerve injuries to improve patients’ quality of life.

The impacts of the COVID-19 pandemic in swimmers: a comparison of daily life activities in pre-restriction and during restriction

Objective: The study aims to compare swimmers’ daily sport life changes caused by the COVID-19 pandemic in the pre-restriction restriction periods. Material and methods: Two hundred fifty-one competitive swimmers participated in this study (117 females), aged 12-33 years, who had at least 3-year sport experience. Data were collected via a Google Forms survey. Statistically, before using a parametric test, the assumption of normality was verified using the Shapiro-Wilk test. A paired t-test was performed for one variable. Variables were presented as frequencies and percentages, according to feedbacks received. The Chi-square test was used to compare variables. Resultsː There were no significant differences related to the changes caused by COVID-19 between genders (p>0.05). Statistically significant increase in training frequency, decrease in swimming training sessions, increase in dry-land training sessions, and changes of daily training time periods occurred during restriction compared with the pre-restriction period. Conclusionsː Findings of this study reveal that the swimmers' athletic lives were negatively affected during the restriction period due to COVID-19.

Separating Nuclear Reactors from the Power Block with Heat Storage to Improve Economics with Dispatchable Heat and Electricity

Markets are changing as the result of (1) the addition of variable wind and solar that causes highly volatile electricity prices and (2) the goal of a low-carbon economy. These changes require economic low-carbon dispatchable electricity, which is now provided by natural gas turbines, and dispatchable heat for industry and commerce. Moreover, nuclear plant requirements have changed in the last 50 years with high capital costs in western countries. An alternative plant design is described with the nuclear island separated from a nonnuclear power block by large-scale heat storage. All heat from the reactor is sent to heat storage. The nuclear reactor operates at base load and is sized to meet average energy demand over a period of days. Heat storage provides variable heat to industry and/or the power block. The nonnuclear power block is sized to provide peak electricity capacity (kilowatts) several times the nuclear reactor base-load power output to maximize revenue by sale of electricity at times of high prices. The power block capital cost (heat exchanger, turbine, and generator) per unit of generating capacity (kilowatt) is less than a conventional gas turbine that includes heat generation (compressor and burner) and the power block (turbine and generator). Nuclear reactor capital cost is reduced by fewer requirements on the nuclear system (not connected to the grid) and nuclear-quality construction for only the reactor. Operating costs (security, maintenance, etc.) are minimized by separation of the nuclear reactor plant from balance of plant. Low-cost heat storage provides a competitive economic advantage to heat-generating technologies (nuclear, concentrated solar power) over electricity-generating technologies (wind, solar, photovoltaic) with more-expensive battery or other electricity storage systems in providing dispatchable electricity to the grid.

Reducing pesticide transport in surface and subsurface irrigation return flow in specialty crop production

This study investigated the transport of 9 pesticides in surface and subsurface irrigation return flow from a container-plant production system over 3 16-day monitoring periods. Pesticides were applied 3 times during the year and the pesticides were selected to provide a range of physiochemical properties. Pesticides are most commonly transported in water and irrigation return flow is a driving factor, therefore, irrigation methods were investigated to determine effects on irrigation return flow volume and transport of pesticides. A control overhead irrigation and two treatments irrigating based on substrate volumetric moisture content (θ) were used. Pesticide transport in irrigation return flow was related to days after application, physiochemical properties and irrigation method. Additionally, pesticide transport was disproportionately reduced, in respect to physiochemical properties, in subsurface irrigation return flow in response to irrigation methods. θ-based irrigation treatments reduced irrigation volume applied by 49% and 77% compared to the control leading to a reduction in the volume of surface irrigation return flow by 71% and 92%. The θ-based treatments reduced the total surface and subsurface volume of irrigation return flow by 52% and 78% versus the control. In most cases, pesticides movement in surface irrigation return flow exhibited a linear or quadratic decrease for the control, while pesticide movement via subsurface irrigation return flow was related more to physiochemical properties limiting mobility rather than irrigation return flow volume or irrigation practice. This study demonstrates pesticide movement in irrigation return flow can be substantially reduced by selecting pesticides with low solubility/high adsorption coefficients whenever possible, and reducing the volume/application of irrigation to non-target areas.

Survival of COVID-19 Patients With Respiratory Failure is Related to Temporal Changes in Gas Exchange and Mechanical Ventilation.

Background: Respiratory failure due to coronavirus disease of 2019 (COVID-19) often presents with worsening gas exchange over a period of days. Once patients require mechanical ventilation (MV), the temporal change in gas exchange and its relation to clinical outcome is poorly described. We investigated whether gas exchange over the first 5 days of MV is associated with mortality and ventilator-free days at 28 days in COVID-19. Methods: In a cohort of 294 COVID-19 patients, we used data during the first 5 days of MV to calculate 4 daily respiratory scores: PaO2/FiO2 (P/F), oxygenation index (OI), ventilatory ratio (VR), and Murray lung injury score. The association between these scores at early (days 1-3) and late (days 4-5) time points with mortality was evaluated using logistic regression, adjusted for demographics. Correlation with ventilator-free days was assessed (Spearman rank-order coefficients). Results: Overall mortality was 47.6%. Nonsurvivors were older (P < .0001), more male (P = .029), with more preexisting cardiopulmonary disease compared to survivors. Mean PaO2 and PaCO2 were similar during this timeframe. However, by days 4 to 5 values for all airway pressures and FiO2 had diverged, trending lower in survivors and higher in nonsurvivors. The most substantial between-group difference was the temporal change in OI, improving 15% in survivors and worsening 11% in nonsurvivors (P < .05). The adjusted mortality OR was significant for age (1.819, P = .001), OI at days 4 to 5 (2.26, P = .002), and OI percent change (1.90, P = .02). The number of ventilator-free days correlated significantly with late VR (−0.166, P < .05), early and late OI (−0.216, P < .01; −0.278, P < .01, respectively) and early and late P/F (0.158, P < .05; 0.283, P < .01, respectively). Conclusion: Nonsurvivors of COVID-19 needed increasing intensity of MV to sustain gas exchange over the first 5 days, unlike survivors. Temporal change OI, reflecting both PaO2 and the intensity of MV, is a potential marker of outcome in respiratory failure due to COVID-19.

Sea-Air Exchange of Methane in Shallow Inshore Areas of the Baltic Sea

We report sea-air fluxes of methane in physically and biologically distinct inshore habitats of the Baltic Sea with the goal to establish empirical relationships that allow upscaling of local site-specific flux measurements. Flux measurements were conducted using floating chambers with and without bubble shields, and by using a boundary layer gas transfer model before, during, and after an annually occurring algal bloom from June to October 2019. Water and air temperature, salinity, wind, sediment organic content, and organic content of floating algal biomass were found to successfully discriminate the different habitats in terms of methane flux, both over periods of days and over a season. Multivariate statistical analysis was used to establish the relative environmental forcing of methane emissions over one growth season for each flux method. Floating algal biomass carbon and sediment organic content were identified as the most important controlling factors for methane emissions based on flux chamber measurements over a period of days to weeks, whereas water and air temperature and wind velocity were the most important factors based on the gas transfer model on these time scales. Over the season, water and air temperature were the most important controlling factors with both methods. We present a first attempt how our observations can be extrapolated to determine the coastal methane emission along the coastline.

Repeating fast radio bursts from collapses of the crust of a strange star

SummaryStrange stars (SSs) are compact objects made of deconfined quarks. It is hard to distinguish SSs from neutron stars as a thin crust composed of normal hadronic matter may exist and obscure the whole surface of the SS. Here we suggest that the intriguing repeating fast radio bursts (FRBs) are produced by the intermittent fractional collapses of the crust of an SS induced by refilling of materials accreted from its low-mass companion. The periodic/sporadic/clustered temporal behaviors of FRBs could be well understood in our scenario. Especially, the periodicity is attributed to the modulation of accretion rate through the disk instabilities. To account for a ~16-day periodicity of the repeating FRB source of 180916.J0158+65, a Shakura-Sunyaev disk with a viscosity parameter of 0.004 and an accretion rate of 3 × 1016 g s−1 is invoked. Our scenario, if favored by future observations, will serve as indirect evidence for the strange quark matter hypothesis.

Embryo-to-embryo communication facilitates synchronous hatching in grasshoppers

Synchronous hatching within single egg clutches is moderately common in locusts and other insects and can be mediated by vibrational stimuli generated by adjacent embryos. However, in non-locust grasshoppers, there has been little research on the patterns of egg hatching and the mechanisms controlling the time of hatching. In this study, the hatching patterns of six grasshoppers (Atractomorpha lata, Oxya yezoensis, Acrida cinerea, Chorthippus biguttulus, Gastrimargus marmoratus, and Oedaleus infernalis) were observed under various laboratory treatments. Under continuous illumination and a 25/30°C thermocycle, the eggs of these grasshoppers tended to hatch during the first half of the daily warm period. Eggs removed from egg pods and cultured at 30°C tended to hatch significantly earlier and more synchronously when kept in groups vs. singly. In general, eggs hatched earlier when egg group size was increased. Egg hatching was stimulated by hatched nymphs in some species, but not in others. In all species, two eggs separated by several millimeters on sand hatched less synchronously than those kept in contact with one another, but the hatching synchrony of similarly separated eggs was restored if they were connected by a piece of wire, suggesting that a physical signal transmitted through the wire facilitated synchronized hatching. In contrast, hatching times in the Emma field cricket, Teleogryllus emma, which lays single, isolated eggs, were not influenced by artificial clumping in laboratory experiments. These results are discussed and compared with the characteristics of other insects.

Impact Of COVID-19 Stay At Home Public Health Restrictions On Physical Activity

The public health response to the COVID-19 pandemic may have changed recreational physical activity behavior. Due to ‘Stay at Home’ restrictions, gyms and indoor exercise facilities were closed by public health orders in many states. PURPOSE: To understand how recreational physical activity behaviors changed based on state-wide COVID-19 Stay at Home restrictions. METHODS: Data on recreational physical activity behavior from three time periods were collected via a retrospective internet survey (n = 144) based on a modified International Physical Activity Questionnaire. Respondents reported days per week and duration of walking, vigorous, and moderate physical activity before, during, and after Stay at Home restrictions in a Western state (March 26 - May 1, 2020.) Days per week data were analyzed across time periods with a one-way repeated measures ANOVA. Friedman’s test was used to analyze minutes per week data across time periods. RESULTS: The one-way ANOVA examining days of vigorous physical activity showed a significant effect (F(2,286) = 4.48, p = .012). Post hoc analysis using the Holm correction revealed a statistically significant decrease in days of vigorous physical activity from before to after restrictions (mean difference = .39 days, p = .014). The analysis of weekly minutes of activity showed a significant difference between time periods for walking (Χ2(2) = 22.44, p < .001). Conover’s post hoc comparisons with Bonferroni correction indicated minutes of walking were greater during the restrictions (Mdnd = 150) compared to before (Mdnb = 110, p < .001) and after (Mdna = 120, p = .002). Vigorous physical activity was also different across time periods (Χ2(2) = 6.73, p = .035), with median vigorous physical activity being lower after restrictions (Mdna = 90) than before (Mdnb = 120) with p = .039. CONCLUSIONS: COVID-19 restrictions had an impact on recreational physical activity. Walking minutes per week increased during restrictions and returned to pre-restriction levels afterwards, with no significant change in number of days of walking per week. Vigorous activity decreased across the time periods in days and duration and did not return to initial levels. It may be important to consider and promote alternative physical activity options in public health situations that require restrictions.

Do alcohol-related consequences and how they are evaluated predict consumption during and days until the next drinking event?

Objective: Alcohol-related consequences are most often examined as outcomes of alcohol use. However, it is also possible that experiencing consequences may predict future drinking behavior. The predictive power of consequences on future drinking behavior may involve both objective experiences of consequences and subjective evaluations of those consequences (i.e., how positive, how negative). The purpose of the present study was to understand how positive and negative alcohol-related consequences-and evaluations of those consequences-predict elements of the next drinking event among college students. Method: 96 participants reported alcohol use and related consequences over a 28-day daily assessment period. Results: Survival analysis and multilevel modeling were used to examine the influence of positive and negative consequences from a given drinking event on latency to and number of drinks consumed at the next drinking event. Contrary to hypotheses, subsequent drinking was not impacted by recent consequences nor how they were perceived. Conclusions: Though theoretically, experiencing alcohol consequences may impact proximal drinking behavior, findings suggest that, in the current sample, other factors have greater importance in the latency between drinking events and amount of alcohol consumed. Future work should continue to identify event-level predictors that impact behavior at the next drinking event, and ways drinkers attempt to avoid repetition of drinking consequences other than simply drinking less (e.g., protective behavioral strategies), as such factors would be valuable targets for intervention. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Prospective changes in sleep problems in response to the daily rest period among Japanese daytime workers: A longitudinal web survey.

SummaryThe daily rest period (DRP) is the daily inter‐work interval and can include a sleep opportunity, leisure time, and other non‐work time. A longer DRP may allow workers to increase time in bed (TIB) and adjust sleep timing, and that may reduce sleep problems such as short sleep duration, sleep debt, social jetlag, and poor sleep quality. The present study examined the longitudinal association between the DRP and these sleep problems among Japanese daytime workers. The DRP, TIB on workdays, sleep quality (Pittsburgh Sleep Quality Index [PSQI]), sleep debt and social jetlag were measured in November 2016 (n = 10,000) and February 2019 (n = 3,098). Of these, 955 permanent daytime workers were divided into five groups based on the change in the DRP duration: shortened ≥2 hr, shortened ≥1 hr, no change (<1 hr), extended ≥1 hr and extended ≥2 hr. Linear mixed‐model analysis revealed significant interaction (group × time) effects on the TIB, PSQI score and sleep debt (all p < 0.001), but not on social jetlag (p = 0.476). Post hoc comparisons revealed that the TIB was decreased, and the sleep debt was increased in the shortened ≥2 hr group, whereas the TIB was increased and PSQI score was improved in the extended ≥2 hr group (all p < 0.01). These findings suggest that an extension of the DRP improves sleep quantity and quality but not sleep debt and social jetlag. Aside from extending the DRP, ensuring a sufficient sleep duration and adjusting sleep timing during the DRP may also be needed to prevent sleep problems.

Effects of the Use of Tourniquet in Total Knee Arthroplasty on the Clinical and Functional Outcomes with 5 Years of Follow-up: A Randomized Controlled Trial.

The use of tourniquet in total knee arthroplasty (TKA) had a lot of controversies with no clear agreement about the advantages and disadvantages of tourniquet. This study aims to show the effects of tourniquet use in TKA on the functional and clinical outcomes with follow-up of 5 years. This is a randomized, double-blind, and single-center study of 101 patients who were treated by TKA and divided randomly into two groups. Tourniquet was used in group A and was not used in group B. Both groups were assessed by Knee Society score (KSS), knee injury and osteoarthritis outcome score (KOOS), visual analogue scale (VAS) score for thigh pain, and postoperative complications. Both groups were followed up for 5 years. The group of no tourniquet showed significant better functional outcomes measured by KSS at postoperative periods of 2 weeks (p = 0.001), 6 weeks (p = 0.006), and 3 months (p = 0.034), and KOOS at postoperative periods of 2 weeks (p = 0.001), 6 weeks (p =0.001), and 3 months (p = 0.016). However, there was no significant difference in long-term follow-up of 5 years. There were significantly better results with use of tourniquet regarding surgeon's visualization during surgery, less operative time, and less calculated blood loss, while significantly better results with no use of tourniquet were reported regarding less hospital stay, less postoperative analgesic consumption, and less postoperative thigh pain measured by VAS score at postoperative periods of day 1 (p = 0.001), day 5 (p = 0.001), 2 weeks (p = 0.001), and 6 weeks (p = 0.001). Regarding postoperative blood transfusion and clinical deep venous thrombosis, there was no significant difference between use of tourniquet or not. The evidence presented in this level-1 randomized controlled trial suggests that no use of tourniquet in TKA can improve functional outcomes in early postoperative period with no significant difference on functional outcome at 5 years of follow-up.

Working with Respiratory Illness: Presenteeism Among Healthcare Personnel at Tertiary-Care Hospitals in Bangladesh, 2008–2016

Background: Healthcare personnel (HCP) in crowded and resource-poor countries (eg Bangladesh), might be at risk of exposure to and transmission of respiratory illnesses to coworkers, patients, and caregivers. The infection control practices in public hospitals are inadequate in Bangladesh. We estimated the incidence of respiratory illness episodes among HCP, and proportion of HCP who worked during respiratory illnesses, including influenza virus infection, at 2 tertiary-care public hospitals in Bangladesh. Methods: From May 2008 to February 2016, HCP (defined as physicians, nurses, interns, patient care assistant, cleaners, and administrative staff working in adult and pediatric medicine wards) were asked to self-report to study physicians when they experienced new onset of cough, rhinorrhea, difficulty breathing, or fever during the April–September influenza epidemic period each year. Study physicians followed HCP throughout their respiratory illness episodes and recorded respiratory symptoms, onset dates, duration of illness, and days of presenteeism and absenteeism during illness. Nasopharyngeal and oropharyngeal swabs were collected after informed written consent and were tested for influenza by rRT-PCR. We used hospital records to enumerate total HCP working in the study wards during influenza season and multiplied by 6-months follow-up per year to calculate person-time contribution for estimating respiratory illness incidence. Results: HCP self-reported 107 episodes of respiratory illness during 656 person years of follow-up, for an estimated incidence of 16.3 per 100 person years (95% CI, 13–20). Of 107 episodes, 33 (31%) included fever and cough. The mean illness length was 3.9 days (SD, ±1.8). HCP worked an average of 3.4 days (SD, ±1.4) while ill. HCP missed work for a median of 1 day (IQR, 1–2) during 29 (27%) of 107 illness episodes. HCP consented to collect swabs during 56 (52%) episodes, and among them 8 (14%) of 56 tested positive for influenza (flu-A, n = 5; flu-B, n = 3). Also, 63% of HCP with influenza reported fever and cough. HCP experiencing either respiratory illness or influenza worked for similar periods of days while ill: mean, 4 (SD, ±2.2) versus mean, 3.3 (SD, ±1.4) (P = .257). HCP worked during 105 (98%) of 107 respiratory illness and 7 (88%) of 8 influenza episodes. Conclusions: Most HCP in Bangladesh, including those with influenza, worked during respiratory illnesses. The potential value of stay-at-home policies, compensation for sick days, and influenza vaccination in reducing HCP-associated respiratory pathogen transmission could be assessed in Bangladesh and similar settings.Funding: NoDisclosures: None

Severe pantothenic acid deficiency induces alterations in the intestinal mucosal proteome of starter Pekin ducks

BackgroundPantothenic acid deficiency (PAD) results in growth depression and intestinal hypofunction of animals. However, the underlying molecular mechanisms remain to be elucidated. Mucosal proteome might reflect dietary influences on physiological processes.ResultsA total of 128 white Pekin ducks of one-day-old were randomly assigned to two groups, fed either a PAD or a pantothenic acid adequate (control, CON) diet. After a 16-day feeding period, two ducks from each replicate were sampled to measure plasma parameters, intestinal morphology, and mucosal proteome. Compared to the CON group, high mortality, growth retardation, fasting hypoglycemia, reduced plasma insulin, and oxidative stress were observed in the PAD group. Furthermore, PAD induced morphological alterations of the small intestine indicated by reduced villus height and villus surface area of duodenum, jejunum, and ileum. The duodenum mucosal proteome of ducks showed that 198 proteins were up-regulated and 223 proteins were down-regulated (> 1.5-fold change) in the PAD group compared to those in the CON group. Selected proteins were confirmed by Western blotting. Pathway analysis of these proteins exhibited the suppression of glycolysis and gluconeogenesis, fatty acid beta oxidation, tricarboxylic acid cycle, oxidative phosphorylation, oxidative stress, and intestinal absorption in the PAD group, indicating impaired energy generation and abnormal intestinal absorption. We also show that nine out of eleven proteins involved in regulation of actin cytoskeleton were up-regulated by PAD, probably indicates reduced intestinal integrity.ConclusionPAD leads to growth depression and intestinal hypofunction of ducks, which are associated with impaired energy generation, abnormal intestinal absorption, and regulation of actin cytoskeleton processes. These findings provide insights into the mechanisms of intestinal hypofunction induced by PAD.

Effects of defect action level of Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) fragments on quality of wheat flour.

Tribolium castaneum (Herbst) is one of the most important secondary storage pests of all types of flour and flour-based products. The present study focuses on the fragment producing behaviour of T. castaneum in wheat flour during storage and its effect on the quality parameters and defect action level (DAL) of fragments. The US Food and Drug Administration has set a DAL of 75 insect fragments in 50 g of flour. Box-Behnken design was used to optimize the storage conditions (storage period in days and temperature in degrees Celsius) and insect density (numbers) to keep insect fragments below the DAL. Optimization results indicated that the presence of single number of adult of T. castaneum is enough to cross the DAL of insect fragments within a storage period of 21 days at a storage temperature of 30 °C. Insect fragments cause perceptible changes in the quality of wheat flour. When sample attained DAL of T. castaneum fragments in wheat flour,the various quality parameters were analysed in that moisture content of wheat flour was 10.8 ± 0.26%, total colour change was 2.052 (ΔE value), T. castaneum progeny emergence was 19.66 ± 1, uric acid was 1.8 ± 0.16 g kg-1 and microbial count was 7.34 ± 0.5cfu g-1 . Results from the present study indicate that the presence of even a single adult of stored pest in wheat flour should not be ignored. It is mandatory to determine the threshold level and frequent sampling is required to achieve zero tolerance of stored product insects in food commodities. © 2021 Society of Chemical Industry.

Move it or lose it: limb immobilisation results in impaired postprandial skeletal muscle glucose uptake.

Move it or lose it: limb immobilisation results in impaired postprandial skeletal muscle glucose uptake.

Long-Distance Movement over a Period of Days by a Female Myotis lucifugus in Newfoundland, Canada

Myotis lucifugus (Little Brown Myotis) is a regionally migrating bat, widely distributed throughout North America. Through long-term monitoring systems deployed in 2 locations in Newfoundland, Canada, we recorded the movement of an adult female of at least 375 km over a period of 4 nights. Although not the longest travel distance recorded for this species, this observation emphasizes the capabilities of Little Brown Myotis for long-distance flights, the potential connectivity among distant maternity groups, and the value of long-term monitoring programs. To fully understand the movement patterns of Little Brown Myotis, advancements in technology and greater research effort are needed.

Representational drift in primary olfactory cortex.

Perceptual constancy requires the brain to maintain a stable representation of sensory input. In the olfactory system, activity in primary olfactory cortex (piriform cortex) is thought to determine odour identity1-5. Here we present the results of electrophysiological recordings of single units maintained over weeks to examine the stability of odour-evoked responses in mouse piriform cortex. Although activity in piriform cortex could be used to discriminate between odorants at any moment in time, odour-evoked responses drifted over periods of days to weeks. The performance of a linear classifier trained on the first recording day approached chance levels after 32days. Fear conditioning did not stabilize odour-evoked responses. Daily exposure to the same odorant slowed the rate of drift, but when exposure was halted the rate increased again. This demonstration of continuous drift poses the question of the role of piriform cortex in odour perception. This instability might reflect the unstructured connectivity of piriform cortex6-12, and may be a property of other unstructured cortices.

Testing the ‘two water worlds’ hypothesis under variable preferential flow conditions

AbstractWidespread observations of ecohydrological separation are interpreted by suggesting that water flowing through highly conductive soil pores resists mixing with matrix storage over periods of days to months (i.e., two ‘water worlds’ exist). These interpretations imply that heterogeneous flow can produce ecohydrological separation in soils, yet little mechanistic evidence exists to explain this phenomenon. We quantified the separation between mobile water moving through preferential flow paths versus less mobile water remaining in the soil matrix after free‐drainage to identify the amount of preferential flow necessary to maintain a two water world's scenario. Soil columns of varying macropore structure were subjected to simulated rainfall of increasing rainfall intensity (26 mm h−1, 60 mm h−1, and 110 mm h−1) whose stable isotope signatures oscillated around known baseline values. Prior to rainfall, soil matrix water δ2H nearly matched the known value used to initially wet the pore space whereas soil δ18O deviated from this value by up to 3.4‰, suggesting that soils may strongly fractionate 18O. All treatments had up to 100% mixing between rain and matrix water under the lowest (26 mm h−1) and medium (60 mm h−1) rainfall intensities. The highest rainfall intensity (110 mm h−1), however, reduced mixing of rain and matrix water for all treatments and produced significantly different preferential flow estimates between columns with intact soil structure compared to columns with reduced soil structure. Further, artificially limiting exchange between preferential flow paths and matrix water reduced bypass flow under the most intense rainfall. We show that (1) precipitation offset metrics such as lc‐excess and d‐excess may yield questionable interpretations when used to identify ecohydrological separation, (2) distinct domain separation may require extreme rainfall intensities and (3) domain exchange is an important component of macropore flow.

Spatial demand forecasting based on smart meter data for improving local energy self‐sufficiency in smart cities

The use of distributed energy resources (DERs) in a city contributes to the net zero CO2 of a city. However, the spatially uneven distribution of power demand and surplus electricity causes congestion in the grid system, making wide-area operation difficult. The concept of local energy self-sufficiency via energy management, in which batteries or electric vehicles are charged using power generated by DERs and discharged to neighbouring consumers, is expected to be a way to avoid grid conjunction while maximizing the use of DERs. For efficient local energy self-sufficiency, it is necessary to identify where and when future power surpluses and shortages will occur within a city and optimize battery operation according to demand. Forecasts that focus only on representative points of a city may be less reproducible in diversity in the power demand transition for individual consumers in local parts of cities. Electricity smart meters that monitor power demand every 30 min from each consumer are expected to help predict the spatiotemporal distribution of power demand to achieve efficient local energy self-sufficiency. The significance of reflecting regional characteristics in forecasting spatiotemporal distribution of power demand is demonstrated using actual data obtained by smart meters installed in Japanese cities. The results suggest that the forecast approach, which considers the daily periodicity of power demand and weather conditions, obtains high prediction accuracy in predicting power demand in meshed local areas in the city and derives results precisely reproducing the spatiotemporal behaviours of power demand.