Length Frequency Research Articles

Integrating data from cold-water coral habitats increase knowledge on age and growth studies: the case of Helicolenus dactylopterus (Delaroche, 1809) in the central Mediterranean

The aim of this study is to provide new insights on the age and growth of H. dactylopterus in the north-western Ionian Sea (central Mediterranean) by using different data sets and comparing three different methods, one direct by otolith reading corroborated by two indirect methods, by means of back calculation and Length Frequency Distribution analysis (LFDa), in order to obtain robust data for use in analytical management models. A total of 1403 specimens of blackbelly rosefish were sampled from habitats explored on muddy bottoms in the depth range 106-721 m and 309 individuals caught in the cold-water coral habitat between 418 and 635 m in depth. The length-frequency distributions of blackbelly rosefish showed a polymodal pattern in both habitats explored, with medium-small individuals caught on muddy bottoms and larger ones in coral habitats and canyons. The maximum age observed in females was 13 years (315 mm TL), while in males it was 15 years (336 mm TL), and no significant difference was observed comparing age-length keys from otolith readings of females with the males. The analysis of the daily increments allowed us to validate the average length of the first year of age (approximately 90-100 mm LT) obtained from the three different methods used. No significant difference was highlighted comparing the average lengths of age class 1, calculated with the direct method and by counting the daily increments. The von Bertalanffy growth parameters were estimated for the sexes and for the whole population from otolith readings and for the entire population by LFD analysis and the back calculation method. The growth curves were comparable between the different methods and no significant difference was observed. The von Bertalanffy growth parameters estimated for the different methods were comparable (otolith readings L∞ 494 mm, k=0.06 years-1, t0=-3.00 years; back calculation method L∞ 487 mm, k=0.06 years-1, t0=-2.30 years; LFDa L∞ 415 mm, k=0.07 years-1, t0=-2.23 years), indicating a slow growth in accordance with what has already been observed in other areas of the Mediterranean.

New technology: clinical efficacy of intracapsular decompression and supported hollow screw treatment for Garden IV femoral neck fractures.

The management of Garden IV femoral neck fractures presents a formidable challenge. This study aimed to assess the safety and efficacy of a novel technological approach for treating Garden IV femoral neck fractures, involving intracapsular decompression and the utilization of supported hollow screws. Between October 2018 and October 2021, a cohort of 46 patients, comprising 25 males and 21 females, was admitted for Garden IV femoral neck fractures. The surgical intervention employed a novel methodology, involving closed reduction of femoral neck fractures on a traction bed and percutaneous implantation of decompression support hollow screw internal fixation in the capsule. Operative parameters such as intraoperative bleeding volume, incision length, and fluoroscopy frequency were recorded. Postoperative angiography was performed to evaluate the blood supply to the femoral neck and femoral head, while long-term follow-up records documented femoral neck fracture healing and patient functional recovery. The closed reduction and minimally invasive implantation of decompression support screws in the femoral neck capsule proved effective in successfully fixing Garden IV femoral neck fractures. The screw placement time was 20-45min, with an average of 25.2min. The number of fluoroscopy was 6-14, with an average of 7. The postoperative follow-up was 20-25months, with an average duration of 22months. All patients exhibited uneventful single-stage wound healing, devoid of complications such as nerve, blood vessel, or important tissue structure injuries. While femoral head necrosis occurred in one case and femoral neck shortening in another, all femoral neck fractures exhibited healing. Post-surgery, patients experienced rapid recovery, enabling early functional exercise with satisfactory functional restoration. The innovative technology, employing femoral neck capsule decompression support hollow screws, not only offers structural support, but also facilitates capsule decompression post-femoral neck fracture surgery. This approach promotes the restoration of blood flow to the femoral head and neck, accelerates fracture healing, diminishes the likelihood of femoral head necrosis, and enhances the overall therapeutic outcome for Garden IV femoral neck fractures. The merits of this novel technique warrant its widespread adoption and application.

Laboratory Simulations of Plasma Generated Around the Atmospheric Reentry Spacecraft

In this paper, plasma will be generated in a laboratory as a simulation of what happens to spacecraft when they enter the atmosphere of Earth. Parameters of plasma generation were determined in terms of pressures of 0.1, 0.2, 0.3, 0.4, and 0.5 mbar and generation energy 200 W. The parameters of the generated plasma were calculated using the optical emission spectroscopy two intensity ratio method, and the electron temperature, electron density, Debye length, and plasma frequency were calculated. Compare the results with the actual results, electron temperatures were 2.26–1.71 eV and plasma frequency 8.09 x1011-6.7x1011 at 0.1-0.5 mbar pressure.

Comparison of dynamic hip screw with anti-rotation screw and femoral neck system internal fixation for the treatment of garden II-IV type femoral neck fractures.

Femoral neck fractures, which are fractures occurring from the femoral head to the base of the femoral neck, are prevalent in the elderly population. With the progression of societal aging, the incidence of femoral neck fractures has been steadily increasing, making it a significant global issue that urgently needs to be addressed. To compare the efficacy and safety of dynamic hip screw (DHS) with anti-rotation screw and femoral neck system (FNS) internal fixation for the treatment of Garden II-IV type femoral neck fractures. A total of 90 patients with Garden II-IV type femoral neck fractures were randomly assigned to either the control group (n= 45) treated with DHS and anti-rotation screw or the experimental group (n= 45) treated with FNS. Surgical outcomes, including incision size, blood loss, operation time, fluoroscopy frequency, and fracture healing time, were compared. Postoperative complication rates, reoperation rates, Harris scores, and visual analogue scale (VAS) scores were also assessed. The experimental group demonstrated significantly reduced incision length, blood loss, operation time, and fluoroscopy frequency compared to the control group (P< 0.01). No significant differences were observed in fracture healing time, Garden classification, or fracture reduction outcomes between the two groups (P> 0.05). At 6 months post-treatment, both groups showed significant improvements in Harris scores and VAS scores compared to pre-treatment (P< 0.05), with no significant differences between the groups (P> 0.05). The rates of internal fixation failure, nonunion, and avascular necrosis of the femoral head, as well as overall incidence of postoperative complications and reoperation rates, showed no significant differences between the two groups (P> 0.05). Both DHS with anti-rotation screw and FNS internal fixation demonstrated comparable efficacy and safety profiles in the treatment of Garden II-IV type femoral neck fractures. The experimental group showed advantages in terms of reduced incision length, blood loss, operation time, and fluoroscopy frequency, while maintaining similar clinical outcomes and complication rates.

The Effect of Season and The Implications For Sustainable Fisheries on The Catch Results of Yellowfin Tuna In Indonesia

This study assessed the purse seine, handline and pole and line catches at PPS (Samudera Fishing Port Kendari) specifically targeting skipjack and yellowfin tuna in the Banda Sea. Although there has been a rise in tuna output over the past two years, the examination of fish size in September until November revealed substantial fluctuation. Additionally, the implementation of the moratorium policy had a detrimental effect. Ensuring the sustainability of fisheries in the Banda Sea, particularly for large pelagic fish like skipjack and yellowfin tuna, necessitates the implementation of adaptive management and selective fishing practices, with a particular focus on enforcing mesh size regulations. The aims of this study were to examine the patterns of tuna fisheries landing at PPS, specifically focusing on the sorts of catches made using purse seine, handline, and pole and line fishing methods. Additionally, the study aimed to assess the length frequency distribution of Thunnus albacares caught using purse seine, handline, and pole and line fishing gear. The methodology offers a thorough framework for eval_uating the sustainability of Thunnus albacares fisheries in PPS Kendari. Policymakers can develop effective management plans for long-term resource sustainability by assessing catch composition, productivity, and size distribution across various fishing gears. The analysis of this study conducted in September - November 2023 revealed that the fish catches varied in size, ranging from 13 cmFL to 124 cmFL.

Life History Traits of Ambassidae Fish, Chanda nama (Hamilton, 1822) From the Old Brahmaputra River of Northeastern Bangladesh

ABSTRACTThe present study provides a comprehensive analysis of the population structure (length–frequency distributions), growth pattern (length–weight relationships [LWRs] and length–length relationships), physiological condition factors (allometric [KA], Fulton's [KF] and relative [KR]), relative weight (WR) and form factor (a3.0) of Chanda nama. A total of 1200 specimens were collected from the Old Brahmaputra River, northeastern Bangladesh, for 12 months by traditional fishing gear, including seine net and cast net. The total length (TL) of several individuals varied from 2.3 to 7.2 cm. The highest percentage contributed to the population's 4.0–4.5‐cm‐sized group. The LWRs indicated a positive allometric growth pattern (b &gt; 3.0). Fulton's condition factor significantly correlated with TL and body weight (p &lt; 0.0001). The calculated WR ranged from 67.38 to 137.64. No significant variations from 100 were found using the Wilcoxon rank test (p = 0.034), suggesting that C. nama might live there in a balanced predator–prey environment. Furthermore, the measured value for the form factor (a3.0) was 0.0105. In addition, fish with a TL of 7–8 cm should be caught since they are in good condition and have enough meat. The study's findings will greatly contribute to the efficient and enduring management of C. nama in the Old Brahmaputra River and its adjacent ecosystems.

Length frequency distribution of yellow-tail fusilier (Caesio Cuning) in several fishing gears in the managed access and reserves of Pasikolaga, Buton Strait Muna Regency

Length frequency distribution of yellow-tail fusilier (Caesio Cuning) in several fishing gears in the managed access and reserves of Pasikolaga, Buton Strait Muna Regency

The function of the Wadden Sea in the life cycle of small pelagic fish

Most fish species require different habitats to complete their life cycle, with coastal areas often playing a crucial role as nursery areas for juveniles. The Wadden Sea is an important nursery area for juvenile fish in the North Sea ecoregion. Despite extensive research on the nursery function of the Wadden Sea for demersal species, its role in the life cycle of small pelagic fish (SPF) remains largely unknown. This limits our understanding of the Wadden Sea ecosystem, as SPF are the dominant component of the overall fish biomass and serve as important food source for higher trophic levels. We studied the role of the Wadden Sea in the life cycle of Atlantic herring (Clupea harengus), European sprat (Sprattus sprattus), European smelt (Osmerus eperlanus) and European anchovy (Engraulis encrasicolus) through monthly stow net and seasonal trawl surveys. Our study showed that SPF use the Dutch Wadden Sea primarily as juvenile habitat, with herring being the dominant marine juvenile representative. Length frequency distributions and genetic analysis revealed that the juvenile herring originated predominantly from southwestern waters, such as the English Channel. Additionally, the Wadden Sea still provides spawning grounds for herring and anchovy, with no substantial spawning observed for sprat. While smelt can complete nearly its entire life cycle in the Wadden Sea, it depends on connectivity to nearby freshwater for spawning. In summary, the Wadden Sea functions as a nursery for juveniles, and to a lesser extent as spawning grounds for adults. A thorough understanding of these functions is crucial for identifying bottlenecks and implementing effective conservation and management strategies.

Growth, mortality, exploitation, and recruitment patterns of Labeobarbus altianalis (Boulenger, 1900) in River Kuja-Migori, Kenya

The Ripon barbel, Labeobarbus altianalis, a riverine fish found in the Lake Victoria Basin is regarded as species of less concern, but it is vulnerable to overfishing and population decline. This study aimed at determining growth, mortality, exploitation rate, and recruitment patterns of L. altianalis (Boulenger, 1900) in River Kuja-Migori. A total of 1,217 specimens with overall total lengths ranging from 9.5-41.5 cm (mean 28.5 ± 2.7) were collected monthly from January to December 2021. The fish were caught using an electrofisher in wadable areas and monofilament nets in deeper areas. Electronic length frequency analysis (ELEFAN) software in Fish Stock Assessment Tools (FiSAT II) program was used to analyze data. Natural mortality (M) Fishing mortality (F) and total mortality (Z) coefficients were 0.15 year-1, 0.52 year-1 and 0.67 year-1 respectively. The asymptotic length (L∞) was 44.94 cm TL while the instantaneous growth rate (K) was 0.15 year-1. The exploitation rate was 0.44 year-1 and the length-based growth performance index (Ø’) was 3.03. Results indicated that the longevity of L. altianalis was 9 years. Recruitment occurs throughout the year with bimodal annual recruitment peaks coinciding with the two rainy seasons in the region. This study provides important information for developing management advice for the L. altianalis riverine fishery.

Fiber morphological characteristics of bamboo Ferrocalamus strictus culms from different geographical distribution regions

The fiber index including fiber length, width, wall thickness and lumen diameter of Ferrocalamus strictus culms (1, 2, and ≥ 3 years) from Jinping, Mojiang and Lvchun counties of Yunnan Province was determined and the elemental content of the soil was also determined to analyze the fiber characteristics. The average relative fiber index measured for F. strictus culms were fiber length (1.30 mm), width (21.57 μm), slenderness ratio (60.79 μm), wall thickness (4.21 μm), lumen diameter (7.22 μm), and runkel ratio (1.22 μm), which belonged to the range of middle and long fibers. The fiber length increased with the culm age. The proportion of long fiber increased while short fibers decreased along with culm maturing. The fiber morphology did not show a specific trend with the culm height. Fiber length reached the maximum in the bottom portions of the culms. There is a correlation between fiber morphology and soil elements, the content of organic matter, total potassium, total sulfur, total aluminum, total zinc, total iron, total boron, alkali-hydrolyzed nitrogen and available silicon in the soil affects fiber morphology. The content of organic matter, total boron and alkali-hydrolyzed nitrogen in the soil from Mojiang County was largest. Comparatively, the culm fiber in Mojiang County had the best fiber index performance for utilization, since the greatest proportion of medium and long fibers and the optimal distribution of fiber length frequency was obtained from the culms in Mojiang County. This study can provide a theoretical basis for large-scale bamboo forest cultivation and the development and utilization of bamboo culm fiber.

A Method for Measuring Word Sequence Complexity of Text

ABSTRACT In linguistics and natural language processing, measuring text features is crucial for representing and revealing the properties of texts in terms of topics, genres, sentiment and more. Current methods predominantly rely on the frequency of linguistic units and rarely consider the syntagmatic properties of these units, which can reflect deeper linguistic characteristics (e.g. syntax and pragmatics). This paper proposes a general method for calculating the sequence complexity of text. By combining the features of word length and word frequency, two specific implementations of this method are provided. Using these two formulas, word sequence complexity of text based on the Brown Corpus and the Gutenberg Corpus is calculated. The results show that word sequence complexity of text indicates a characteristic of gradual stabilization. By comparing random texts with natural texts, it is found that word sequence complexity is influenced by syntactic rules rather than sentence order, and natural texts tend to alternate between words of varying lengths and frequencies. Classification experiment results indicate that the proposed word sequence complexity outperforms commonly used quantitative indicators for representing the genre of text, such as TTR, information entropy, Zipf’s law parameters and motifs.

Efficacy of high-frequency rTMS in the treatment of gait disorder and cognition in patients with Parkinson's disease based on wearable devices and eye-movement assessments.

Postural instability and gait disorder and cognitive dysfunction are common symptoms of Parkinson's disease (PD). Scale assessment is frequently used in the clinic to evaluate PD, but this technique is limited by its lack of sensitivity to changes in disease progression and its difficulty in capturing subtle movements and changes in cognitive function. It is currently believed that high-frequency repetitive transcranial magnetic stimulation (rTMS) can improve motor and cognitive dysfunction in patients with PD, though it remains controversial. Therefore, it is imperative to monitor and dynamically identify changes in postural instability and gait disorder, as well as those in cognitive dysfunction, in PD to develop targeted interventions. In this study, we observed the effect of high-frequency rTMS on gait disorders and cognitive functions in patients with PD by comparing data from wearable devices and eye-tracking devices before and after treatment. A total of 159 patients with PD were included in this study. A GYENNO MATRIX wearable gait analyzer was used to monitor the objective gait data (including the timed up-and-go, narrow-track, and turning tests), the Eyeknow eye-tracking evaluation system was used to monitor the patient's eye movement cognition data (including the smooth pursuit, pro-saccade, and anti-saccade tests), and gait and cognitive function-related scales, including the Tinetti Balance Scale, Tinetti Gait Scale, Berg Balance Scale, Mini-Mental State Examination, and Montreal Cognitive Assessment (MoCA), were evaluated at the same time before and after high-frequency rTMS treatment. The mean step length, mean stride velocity, stride length, and mean step frequency of patients with PD in the timed up-and-go test all increased compared with those before rTMS treatment, whereas the mean stride time and double support decreased. In the narrow-track test, the mean stride velocity increased and the mean stride time decreased. In the turning test, the turning left duration, turning right duration, mean duration, mean number of steps, and average step duration decreased, while the mean angular velocity increased after rTMS treatment. Compared with those before rTMS treatment, the latency period of patients with PD in overlapping saccades decreased, the completion time of overlapping saccades decreased, and the average saccade speed increased. In the anti-saccade test, the completion time decreased and the average saccade speed increased after rTMS treatment. Compared with those before rTMS treatment, the Tinetti Balance Scale, Tinetti Gait Scale, Berg Balance Scale, Mini-Mental State Examination, and MoCA scores increased, and the MoCA sub-items improved in terms of visual-spatial and executive function, language, abstraction, delayed recall, and orientation after rTMS treatment. High-frequency rTMS may be an effective therapy for improving gait disorders and cognitive functions in patients with PD.

Linguistic factors associated with stuttering-like disfluencies in Japanese preschool and school-aged children who stutter

IntroductionStuttering is influenced by different linguistic factors, such as sentence- and word-level factors. However, its developmental differences remain unclear. Thus, this study examined the developmental differences in the linguistic factors associated with stuttering-like disfluencies (SLD) among Japanese preschool and school-aged children who stutter. MethodsWe analyzed utterances from 30 Japanese-speaking children who stutter aged 5–10 years. Participants were divided into three groups according to their age (5–6, 7–8, and 9–10 years old). ResultsSignificant effects of sentence length, bunsetsu length, syllable weight, and bi-mora frequency on SLD frequency were observed across the age groups. In contrast, there was not a significant effect of mora frequency on SLD frequency. ConclusionsBoth sentence- and word-level factors affected SLD in children who stutter aged 5–10 years. Future research should be conducted with children below 5 years of age to observe detailed developmental differences in the linguistic factors that affect stuttering.

Relationship between Repeated Sprint Ability and Force–Velocity Profile in Elite and Subelite Female Field Hockey Players

This study aimed to compare two female field hockey teams of different competitive levels by analyzing kinematic variables in repeated sprint ability (RSA) tests and the force-velocity profile (FVP). Twenty-five female hockey players representing the elite and subelite levels from the same club volunteered to participate. The RSA protocol included six 30 m maximal sprints with a 30 s recovery. Kinematic variables, such as sprint time, step frequency, and step length, were analyzed for each sprint. Additionally, players performed counter-movement jumps (CMJs) and CMJs with 50% body weight (CMJ50s) to calculate the FV50 using the Bosco Index. The elite players showed better (≈2%; p &lt; 0.05) fatigue indexes in sprint time (0–30 m and 0–10 m sections), step length (0–10 m, 10–20 m, and 20–30 m sections), and step frequency (20–30 m section) during the RSA test, as well as greater values (&gt;10%; p &lt; 0.05) in the CMJ50 and FV50 tests. In addition, these RSA (sprint time, step frequency, and step length) and jumping (CMJ, CMJ50, and FV50) variables showed a moderate, significant, or very significant relationship with each other. Therefore, it seems that both strength and speed capacities can be used either in conjunction or as a complementary approach to enhance the overall RSA performance.

Daily snuff use during pregnancy, gestational length and birth weight; register-based study

BackgroundSnuff is a smokeless source of nicotine that is common in Scandinavia and increasingly used by women of fertile age. Persistent use of snuff during pregnancy has been associated with adverse pregnancy outcomes. Emerging data from the Medical Birth Registry of Norway distinguishes between occasional use and daily use. We provide preliminary estimates of associations between frequency of snuff and gestational length and birth weight.MethodsData on snuff use during pregnancies delivered in 2020 and 2021 were available for the west and central regions of Norway. Associations of snuff use with gestational length and birth weight at term (39–41 weeks) were estimated using quantile regression at the 25th, the 50th and the 75th percentiles, with adjustments for mother’s age, pre-pregnancy weight, and parity. We compared associations with the pregnancy outcomes according to maternal snuff and cigarette use.Results12.4% of 18 042 non-smoking women reported daily use of snuff before pregnancy, and 4.6% reported continuing use during pregnancy, with 1.2% still reporting daily use in the last trimester. Women with daily use through the last trimester delivered babies with a median gestational length reduced by 3.4 days (95% CI: -5.0 to -1.7 days) compared with women who never used snuff. The reduction was even stronger at the 25th percentile of gestational age. The median term birth weight was reduced by 44 g (95% CI: -134 to 46 g). These associations were much weaker for women who quit snuff at some point during pregnancy or used snuff only occasionally. Mothers who smoked daily through the last trimester had a median gestational length reduced by 2.1 days (95% CI: -2.7 to -1.4) and a median term birth weight reduced by 294 g (95% CI: -325 to -262) compared with never-smokers.ConclusionsDaily snuff use through the last trimester reduced the median gestational length by more than three days. Snuff reduced birth weight, but not as much as smoking, suggesting that the predominant effect of smoking on fetal growth is not through nicotine but through the additional toxic chemicals in cigarettes or by reduced oxygen supply to the fetus.

Disruption of natural disturbance regime decouples habitat and life stage in a keystone species

AbstractAnthropogenic disturbance of stream ecosystems, often chronic in nature, has been studied extensively. However, when disturbance is driven by more than one resource policy over many decades, feedback between habitat evolution and biological adaptation can be disrupted and ecological function affected in unforeseen ways. We analyzed over 100 years of Chinook salmon (Oncorhynchus tshawytscha) length frequency trends associated with fisheries management and changes in available spawning substrate (habitat) linked to flow regulation in a highly altered California river. Over time, salmon lengths generally decreased, fluctuating with exploitation (ocean harvest) and hatchery production rates. Female size reduction, coupled with a degrading and coarsening channel, and perching peripheral habitat related to past mining activity, indicates available spawning substrate may be too large to support the current salmon population. Assuming a salmon can move material ~10% of her body length, length frequency data and current substrate size distribution suggest that increasing salmon sizes to historic distributions could increase available spawning habitat by as much as 13%. Alternatively, decreasing spawning substrate size could support a greater portion of the current population. To test the latter hypothesis and inform future management actions, we monitored two spawning riffles where large and small gravel was placed on top of a cobble. We observed an immediate spawning activity increase that was more pronounced where smaller gravel was deposited. Following a decade of habitat decline, the two sites were both replenished with medium gravel. Elevated spawning use occurred immediately at both sites, commensurate with this intermediate size, further supporting our hypotheses. Sediment coarsening and habitat disconnect below dams, combined with reduced salmon size, indicate the natural spawning process may be decoupled from available habitat below dams in the foreseeable future without continuous intervention. Actively managing salmon population demographics through modified hatchery and size‐selective harvest practices and developing a coarse sediment budget with size‐appropriate material for regulated anadromous rivers could produce immediate benefits for ecosystem services, including salmon populations. However, these management actions will require continued maintenance and informed socio‐ecological goals to remain successful.

Switchable SAW Resonators and Ladder Filters Composed of Interdigitated Combs.

This work presents the development of switchable surface acoustic wave (SAW) resonators fabricated on a LiNbO3 substrate, which uses the electrical Bragg bandgap concept to control the resonance frequency. The modification of the electrical condition of electrode arrays shifts their bandgap center frequency, which in turn changes the effective cavity length and resonance frequency of the resonator. This method uses the electrodes already present in SAW devices, thus reducing the complexity of potentially tunable SAW components. In this article, the electrodes that make up the cavity mirrors are connected into interdigitated comb pairs (IDCPs), reducing the necessary number of switches for operation. Finite-element method (FEM) simulations are used to analyze resonator operation and design difficulties are discussed. Frozen (with no possibility of switching) and switchable versions of a chosen resonator structure are fabricated to experimentally showcase resonator operation. It is found that it is possible to design switchable SAW resonators, which require a single switch and present a relative frequency jump of around 2.3%. Finally, frozen single-cell and four-cell ladder filters are fabricated as a proof of concept of a switchable SAW filter.

Oxygen Consumption In Vivo by Ultra-High Dose Rate Electron Irradiation Depends Upon Baseline Tissue Oxygenation

Purpose: This study aimed to assess the impact of tissue oxygen levels on transient oxygen consumption induced by ultra-high dose rate (UHDR) electron radiation in murine flank and to examine the effect of dose rate variations on this relationship. Methods: Real-time oximetry using the phosphorescence quenching method and Oxyphor PdG4 molecular probe was employed. Continuous measurements were taken during radiation delivery on a UHDR-capable Mobetron linear accelerator (linac). Oxyphor PdG4 was administered into the subcutaneous tissue of the flank skin one hour before irradiation. Skin oxygen tension (pO2) was manipulated by adjusting oxygen content in the inhaled gas mixture and/or by vasculature compression. A skin surface radiation dose of 19.8±0.3Gy was verified using a calibrated semiconductor diode dosimeter. Dose rate was varied across the UHDR range by changing linac cone length and pulse repetition frequency (PRF). Results: The decrease in pO2 per unit dose during radiation delivery, termed oxygen consumption g-value (gO2, mmHg/Gy), was significantly influenced by tissue oxygen levels in the range 0-65mmHg under UHDR conditions. Within the 0-20mmHg range, gO2 exhibited a sharp increase with rising baseline pO2, plateauing at 0.26mmHg/Gy. Dose rate variations (mean values 25-1170Gy/s, per-pulse doses of 2.5-9.8Gy) were explored by varying both cone length and PRF (10-120Hz) with no significant changes in gO2. Conventional dose rate irradiation resulted in no discernible changes in pO2. Conclusions: The results show significant differences in the radiation-chemical effects of UHDR radiation between hypoxic and well-oxygenated tissues. Similar trends between earlier published in vitro and in vivo experiments presented herein suggest the chemical mechanisms driving the dependencies of gO2 on pO2 are similar, potentially underpinning the FLASH effect. Importantly, significant variations in baseline pO2 were observed in animals kept under identical conditions, underscoring the necessity to control and monitor tissue oxygen levels for preclinical investigations and future clinical applications of FLASH-RT.

Estimates of life-history and growth parameters of exploited fish species in lakes Edward and George: Implications on exploitation status, population dynamics, management, and conservation of native species.

Adequate knowledge is essential for responsible inland fisheries. However, many inland fisheries lack monitoring, and therefore, decision-making for fisheries management is not reliable. In this paper, we used data from surveys and literature to estimate the life-history and growth parameters of 16 exploited fish stocks in the Ugandan part of Lake Edward and Lake George (East Africa). The estimated parameters are pivotal indicators of fish stock status, particularly in data-poor fisheries. The estimated parameters included maximum length (Lmax) and mean length (Lmean) as indicators of size structure in experimental and commercial catches, coefficients of length-weight relationships, length at 50% maturity (Lm50), fecundity, von Bertalanffy parameters, total mortality (Z), and natural mortality (M). These parameters were estimated using empirical formulae, statistical methods, and analyses of length frequencies. Only two stocks of semutundu Bagrus docmak exhibited significant and increasing trends in Lmax (Lake Edward) and Lmean (Lake George). The estimates for the remaining parameters were consistent with those in FishBase and other literature resources, either for the same species or related species. This consistency indicates their reliability for application in decision-making and further assessments. Some parameters showed evidence of unsustainable fishing. For example, estimates of Lm50 for four of the assessed stocks belonging to two species (Nile tilapia Oreochromis niloticus and marbled lungfish Protopterus aethiopicus) were lower than baseline estimates in the studied waterbodies. Furthermore, the Lmean in catches for all the stocks were less than the optimum lengths (Lopt), which maximize catches with a minimal impact on biomass and size structure. No significant changes in Lmean, length-frequency distributions, and size at maturity could be attributed to the management changes implemented in 2018, probably because it is too early to observe changes in these parameters. However, there are positive signs attributable to the changes in management as shown by a high proportion of mature individuals in commercial catches for most of the stocks for which the proportion was calculated, and an increase in Lmean and Lmax for some stocks, such as B. docmak, in commercial or experimental catches. New estimates from this study will enhance decision-making and further assessments of fisheries. Routine monitoring is recommended to update and improve the estimates.

Stock status and spawning potential ratio of orange mud crab (Scylla olivacea, Herbst 1796) in the southwestern coastal waters of Bangladesh

Scylla olivacea (Orange mud crab) is a second commercial invertebrate species exported from Bangladesh. Though a significant portion of exports are supported by aquaculture, their farming ultimately depends on their wild stocks. Unfortunately, unregulated exploitation has led to a significant decline in the natural biomass of this species, raising concerns about the sustainability of crab production in Bangladesh. The study aimed to assess the stock status of S. olivacea (Orange mud crab) from the Southwestern coastal water of Bangladesh. One-year length frequency (width frequency-WF for crustacean fishery) data were collected and analyzed using the LBB (Length-based Bayesian Biomass) and LB-SPR (Length-based spawning potential ratio) methods. The assessed width parameter depicted the exploitation of small-size individuals (Wc=< Wc_opt) of S. olivacea. The estimated B/B0 (0.25) suggests that 75 % of the wild stock had already been harvested, and biomass cannot produce MSY. The mean estimates for SW50 % and SW95 % were 8.29 cm and 12.76 cm respectively, revealing the use of a small mesh-size net for crab harvesting. The assessed Spawning Potential Ratio (SPR) was 12 % which is below the SPR limit reference point (SRP) of 20 %. This research confirmed the overfished (F/M = 1.4) and overexploited (E = 0.58) status of S. olivacea in Bangladesh. To ensure the sustainability of coastal fisheries in Bangladesh, the authorities must take immediate management measures to control the overexploitation of this species.