Maturity Length Research Articles

Life‐history traits of three Ambassid fishes (Chanda nama, Parambassis lala and Parambassis ranga) from the Mathabhanga River, southwestern Bangladesh

ABSTRACTThe present study provides the first indication of the life‐history traits, including, population structure, growth pattern, condition factor, form factor (a3.0), size at first sexual maturity (Lm), natural mortality (MW) and optimum catchable length (Lopt), of three Ambassid (Chanda nama, Parambassis lala and Parambassis ranga) fishes from the Mathabhanga River in southwest Bangladesh. A total of 370 individuals were occasionally collected from August 2017 to July 2018 with cast nets, gill nets, square lift nets, and conical‐ and box‐traps. The total length (TL) ranged from 2.4 to 7.5 cm for C. nama, 1.9–3.8 cm for P. lala and 1.8–6.5 cm for P. ranga. The length‐frequency distributions (LFDs) showed the 4.0–5.0 cm TL size group for C. nama and the 3.0–4.0 cm TL size group were numerically dominant for P. lala and P. ranga. The length–weight relationships (LWRs) indicated isometric growth for C. nama, and positive allometric growth for P. lala and P. ranga. All the LWR values were very significant (p < .001), with all r2 values > .950. Based on the Spearman rank correlation test, body weight (BW) versus Fulton's‐condition factor (KF) was extremely correlated (p < .001), indicating a better wellbeing for these species. The a3.0 value was 0.0082, 0.0138 and 0.0104 for C. nama, P. lala and P. ranga, respectively. Based on the maximum length (Lmax), the Lm was 4.4 cm TL for C. nama, 2.5 cm TL for P. lala, and 4.0 cm TL for P. ranga. Based on the asymptotic length (L∞), the Lm was 4.88 cm TL for C. nama, 2.63 cm TL for P. lala, and 4.28 cm TL for P. ranga. The MW value was 2.2, 3.3 and 2.7/year for C. nama, P. lala and P. ranga, respectively. The optimum catchable length (Lopt) was 5.36 cm TL for C. nama, 2.75 cm TL for P. lala and 4.65 cm TL for P. ranga. The findings of the present study should be very useful for effective and sustainable management of these fishes in the Mathabhanga River and the connecting ecosystems.

Analyzing the Effect of Intensive and Low-Input Agrotechnical Support for the Physiological, Phenometric, and Yield Parameters of Different Maize Hybrids Using Multivariate Statistical Methods

Improving nitrogen efficiency is a crucial strategy for developing sustainable agricultural systems that leads to maximum yield in exchange for minimum inputs and nitrogen loss. Three maize hybrids (Zea mays L.) of different maturity classes and length of vegetation period (FAO 400, FAO 490, and FAO 380) were selected and for trials during the 2019 growing season. Three different nitrogen (N) fertilization treatments (0, 120, and 305 kg·N·ha−1) were applied in order to assess variability in yield-related components. The effect of hybrids, fertilizer, and the interaction of the examined hybrids in relation to fertilizer was significant on yield and oil and protein content. Correlation and biplot analysis show that increases in the lipid peroxidation (LP) amount in the plant leaf stages cause a decrease in the oil content of the harvested yield. The activity of ascorbate peroxidase (APX) and LP at the six-leaf stage directly affects the protein content. The amount of APX at the silking stage has a direct and significant effect on starch content. This study showed that the activity of APX at the silking stage has the highest value in all examined hybrids. APX and LP can be controlled with nitrogen fertilization under various environmental circumstances.

Research Article: Estimation of gillnet mesh size for Narrow-barred Spanish mackerel (Scomberomorus commerson Lacépède, 1800) using girth measurements, Northwest Persian Gulf

This research was conducted in the fishing ground of Bushehr Province in the northern Persian Gulf from October 2018 to June 2019. Scomberomorus commerson specimens were caught using common multifilament drift gillnet with mesh sizes of 130, 140, 150 mm (STR). The main purpose was to determine the proper gillnet mesh size for the prohibition of catching non-adult fish using girth measurements. Fork length, girths were measured at the preopercle (POG), opercula (OG), and first (DF1G) and second dorsal (DF2G) fins. Overall, 1230 specimens were caught during the autumn, winter, and spring seasons. The percentages of immature Narrow-barred Spanish mackerel caught by gillnets with the mesh sizes of 130, 140, and 150 mm (STR) were 69.2% , 66.5% , and 60.3 %, respectively. The estimated equations between fork length and girths were POG=0.2285FL+5.4836 (R2=0.8366), OG=0.2477FL+6.8582 (R2=0.8006), DF1G=0.2851FL+7.0874 (R2=0.8566), and DF2G= 0.3191FL+8.1031 (R2=0.8316). Pearson correlation analysis also showed a positive correlation between the measured girths and fork length (p<0.01). Two-way ANOVA results showed that the effect of mesh size on fork length and girths were significant (p<0.05). Based on the fork length of first sexual maturity (83.6 cm), the use of the estimated mesh size based on the DF2G (17.39 cm) will be essential to reduce the catch of non-adult fish and having sustainable fishing in the future.

Heterogeneity of growth and maturity of Larimichthys polyactis in the offshore waters of southern Zhejiang, China

The variations of life history traits have been observed for many fish species, which gains much concerns in the study of aquatic biology and ecology. In this study, the biological characteristics were explored for yellow croaker (Larimichthys polyactis) in the offshore waters of southern Zhejiang, based on 4920 individuals collected from 13 fishery-independent seasonal surveys from autumn 2015 to autumn 2018. Linear mixed effects models were used to estimate the growth, maturity characteristics, and their heterogeneity. The body length of yellow croaker samples ranged from 13 to 215 mm with the dominant body of 110 to 154 mm. The body weight ranged from 0.5 to 182.2 g, with the dominant body weight from 20 to 55 g. The results showed that the linear mixed effects models with random effects from season, gender, and year performed best for length-weight relationship, with the lowest AIC and RMSE values. The effects of season were much larger than those of genders and years. When the length exceeded 160 mm, the weight gain rate of yellow croaker was faster in spring and summer, lower in autumn and winter, while the male individuals gained more weight than the females with the same body length. Among 4841 individuals of specimens with gonadal data, the individuals at maturity Ⅱ stage occupied 50.4%, and the individuals at maturity stage contributed to 19.6%. The results from the best linear mixed effects model showed that season had the most significant influence on the maturity of yellow croaker. The 50% maturity length (L50%) was much lower in winter (124.6 mm) with no much difference between other seasons, indicating that yellow croaker matures earlier in winter. Our results indicated that linear mixed effect model could reflect the biological heterogeneity of yellow croaker conveniently and that the growth and maturity of yellow croaker had significantly sexual and temporal variations, which should be considered in the stock assessment and fishery management for yellow croaker.

Stock Assessment of Parrotfishes “Molmol” (Sub-Family Scarinae, Family Labridae) in the Major Fishing Grounds of Bohol, Central Visayas

The issue on the overfishing of parrotfishes, locally known as “molmol” (subfamily Scarinae under family Labridae), in the coastal waters of Bohol province in Central Visayas has been raised by the Provincial Agricultural and Fishery Council (PAFC) of Bohol through Resolution No. 1 series of 2018 that pushes for the implementation of “open and closed fishing season” of all parrotfishes in the entire province. In any management intervention, baseline assessment of the stocks in question should be done as a significant basis for appropriate measures to be taken, thus this study. In Bohol, apart from the economic value, they carry essential functions in maintaining the ecological balance in the reef ecosystem. Parrotfishes are considered economically important as preferred fish among locals and tourists. The stock assessment of parrotfishes in Danajon Bank in the Bohol Sea and Cebu Strait was conducted by the National Stock Assessment Program (NSAP) Region 7 from 2015 to 2018 in 16 coastal municipalities of Bohol. It recorded 24 Scarine species across six genera. The green humphead parrotfish (Bolbometopon muricatum), categorized as vulnerable under the International Union for Conservation of Nature (IUCN) red list, was noted in Cebu Strait in 2015. Scarus ghobban, comprising 82.25%, dominated the catch in Danajon Bank; Scarus forsteni (30.07%) in Bohol Sea; and Chlorurus sordidus (58.45%) in Cebu Strait. Among the Scarines, S. ghobban dominated across fishing grounds from 2015 to 2018 with an aggregate of 10,267.69 kg (or 63.94%) monitored catch equivalent to 0.26% relative to all other species surveyed in the same period. The assessment also indicated that among the 22 fishing gear types being observed as used in catching parrotfishes, speargun is the most prevalent or frequently used. Moreover, the same assessment showed that the catch seasonality of S. ghobban determined from spear gun appears to be abundant during the first quarter in a year; in June, August, and December when higher monthly mean Catch per Unit Effort (CPUE) were also noted. However, the annual mean CPUE of speargun has decreased from 11.93 kg/day in 2017 to 9.22 kg/day in 2018. Population parameters of S. ghobban as the top one species were estimated using the FAO-ICLARM Stock Assessment Tools (FISAT) software and Froese Indicator Tool. Biological indicators for S. ghobban show signs of overfishing as reflected on its high fishing mortality (F/M), decreasing average length below maturity length, decreasing catch per unit effort in the current year, low percentage of mature in the catch, and increasing exploitation ratio (E). All of which already breached the limit reference points. In 2017 and 2018, the mature size composition of the catch was only 1.9 percent and 0.3 percent, respectively, far off from the 90-100% target and below the 50% limit. The values indicate that majority of the samples were small sizes; however, it cannot be determined if they were juveniles since this study excludes reproductive sampling. Optimum length (Lopt) was estimated at 29 cm (Total Length); lengths within ± 10% Lopt range at 26.1 to 31.9 cm and megaspawner at 31.9 cm up. Based on the results, suggested recommendations are indicated herein for possible consideration of the policymakers.

Effect of NPS and Nitrogen Fertilizer Rate on Yield and Yield Components of Food Barley (&amp;lt;i&amp;gt;Hordeum vulgare&amp;lt;/i&amp;gt; L.) in Western Oromia, Ethiopia

Inappropriate crop management practices are among the key elements contributed to low productivity of Barley. Moreover, application of balanced fertilizers and nutrient requirements of the crop is the basis to produce more crop yield from the land under cultivation. Accordingly, field experiment was conducted in 2018 & 2019 main cropping season from the mid of July to first of December at Gedo and Shambu research station to identify the optimum amount of NPS and N fertilizer rate and to evaluate the economic profitability of NPS and N fertilizers for Barley production. The experiment was consisted of twenty treatments combined factorial with five NPS (75, 87.5, 100, 112.5 and 125 kg ha-1) and four Nitrogen (17, 23, 29 and 35 kg ha-1) rates keeping the other managements and cultural practices uniform. The experiment was laid out in randomized complete block design with three replication. The pre soil analysis indicated that the soil of experimental area is acidic (pH = 4.99 at Gedo and 4.98 at shambu) and low in available Phosphorus (12 ppm at Gedo and 13 ppm at Shambu). The main effect of days to heading, grain per spike, thousand seed weight and harvest index were not significantly (P>0.05) influenced due to NPS and N rate. Whereas, days to maturity, plant height and panicle length were significantly different (P<0.05) due to the main effects of N rates though not influenced due to NPS rates at Gedo and Shambu. On the other hand, number of effective tiller, grain yield and above ground biomass were highly significantly (P<0.01) influenced due to the main and interaction effect of NPS and N rates at both locations. Among different NPS and N fertilizer rates tested, the combination of 125 NPS and 35 N kg ha-1 rates gave the highest yield thereby resulting in the highest net benefit. Thus, economic analysis indicated that combination of 125 NPS (47.5 P₂O₅, 23.75 N, 8.75 S kg ha-1) and 35 N kg ha-1 rates on HB -1307 variety gave grain yield (3631.79 kg ha-1) with the net benefit (39849.01 birr/ha) and the highest marginal rate of return (992.16%) are economically feasible alternative to the other treatments. Therefore it is advisable to use combination of 125 NPS and 35N kg/ha rates on HB -1307 variety since economically feasible to the farmers. However, to reach at conclusive idea there is future line of work to get the peak point at which this fertilizer combination showed turning point.

The Biological Aspect of Mackerel Scad (&lt;i&gt;Decapterus Macarellus&lt;/i&gt; Cuvier, 1833) In Samudera Hindia (West Sumatera Block)

Mackerel scad (Decapterus macarellus) is one of the important economical caught in the Indian Ocean West Sumatra waters captured using purse seine. Increased production of mackerel scad will lead to increased exploitation, causing population changes. Therefore, research was carried out to find out the biological aspects of the fish so that resource management can be done. The sampling was conducted in Lampulo, Sibolga, and Air Bangis from February to November 2016 with total samples of 716 fishes. This research was conduct to study some biological aspects which consist of size distribution, length-weight relationship, sex ratio, gonad maturity level, the length at first capture, and length of the first maturity in Indian ocean west Sumatera waters. The results showed that the size of the mackerel scad had ranged between 16 - 33.6 cm FL and the average was 24.5 cm. Growth patterns are allometric negative, sex ratio male and female in an unbalanced condition. The mackerel scad is most caught by purse seine in maturity condition. The average length at first captured was 25.08 cm FL and length at first mature was 20.47 cm FL. These were an ideal biological condition and must be maintained because it provides an opportunity for fish to increase the population. The mesh size purse must follow the Ministry of Maritime Affairs and Fisheries Regulation Number 71/2016 that adjusted for minimum at 1 inch. Keywords: Mackerel scad, Indian Ocean, purse seine

A novel perspective on closed-loop supply chain coordination: Product life-cycle approach

Abstract Due to the dynamic nature of product life-cycle (PLC) and exclusive features of different phases, operational and long-term decisions such as supply chain coordination (SCC) may encounter some challenges. However, no studies have been done so far to evaluate the life-cycle impacts on SCC. In this regard, this paper studies a coordination approach in a closed-loop supply chain (CLSC) during the PLC including introduction, growth, maturity, and decline phases. The market demand and return rate functions are characterized according to the different phases as well as time-varying pricing decisions. First, the proposed problem is examined under the decentralized and centralized structures with life-cycle considerations. Then, a hybrid contract inspired by two-part tariff and joint collection cost mechanisms is developed to coordinate the channel. Finally, some numerical experiments and in-depth sensitivity analyses with a focus on different PLC phases are carried out. The results indicate that although the hybrid contract is able to satisfy a Pareto optimal solution in the life-cycle model, it does not necessarily work optimally in individual phases. On the other hand, contrary to the introduction phase, as the length of growth, maturity, and decline phases increase, the profits of channel players increase which implies that in order to design a more profitable PLC structure, a fundamental planning is needed.

Reduction of reproductive parameters of Pogonias courbina (Perciformes, Sciaenidae) in southern Brazil

In southern Brazil, the Southern Black Drum Pogonias courbina is an estuarine-dependent fish, endangered due to intense fishing in the past decades. This study calculated the reproductive parameters, age (A50) and length of first maturation (L50), batch fecundity, total fecundity and extension of the reproductive period of the P. courbina, in order to test the hypothesis of reduction, caused by heavy exploitation. The value for A50, calculated for both sexes, was 2.13 years. The L50 values for males and females were 42.5 and 46.4 cm respectively, while batch and total fecundity were 63,300 and 2,532,000 oocytes, in a reproductive period that extends from late October to March. Except for the extension of the reproductive period, it was observed that there was a reduction of all the reproductive parameters when compared with specimens, caught before overfishing. The data indicate that management strategies aimed at ecological and fishery sustainability are urgent and necessary.

Determining genetic diversity in cotton genotypes to improve variability

A better understanding of genetic diversity in cotton cultivars is needed to make the most of the genetic resources and guarantee continuing improvements in the breeding programs. Our objective was to evaluate the genetic diversity among cotton genotypes from the top breeding programs in Brazil and recommend hybrid combinations that would increase variability. The field experiments we conducted on three cotton genotypes from each of the following Brazilian breeding programs: EMBRAPA, MONSANTO DELTAPINE, FIBERMAX, IMA, TMG and UFU. Several phenotypic evaluations were carried out at V5, B1, full flower and full maturity. Moderate genetic divergence was observed among the genotypes from these breeding programs. Hybridization of the BRS 433 FL B2RF and FM 980 GLT genotypes would likely produce segregating populations with greater genetic variability, yield potential, lint yield and desirable fiber quality. Maturity, micronaire and fiber length were the strongest contributors to genetic divergence.

Marmara Denizi’nde Parapenaeus longirostris (Lucas, 1846)’in biyolojik özellikleri ve populasyon dinamiği

Parapenaeus longirostris is a valuable resource for the crustacean fisheries in the Marmara Sea, therefore, in this study length-weight relationships, growth, mortality, reproduction, recruitment patterns, the probabilities of capture and per recruit analyses were determined. Total 36288 samples were collected by beam trawl between September 2011 and July 2014 in 229 sampling stations. The total length (TL), body weight (g) and carapace length (CL) values ranged between 34 -175 mm, 0.2 - 28.9 g and 8 - 41 mm, respectively. CL-weight relationship equations were calculated for females, males and combined sexes, respectively, W=0.0023×CL2.5, W=0.0029×CL2.43, W=0.0022×CL2.52. The growth parameters were determined as L∞=199.5 mm, k=0.47, t0=-0.5 in TL, L∞=36.8 mm, k=0.37, t0=-0.69 in CL. L25, L50, and L75 values were found to be 15.15 mm, 16.29 mm, 17.44 mm for males and 16.62 mm, 18.07 mm, 19.52 mm for females. The sexual maturity length for females was found 27.3 mm CL and the exploitation rate was found at 0.62 for the whole population.

Are farmers willing to pay for climate related traits of wheat? Evidence from rural parts of Ethiopia

Wheat production in Ethiopia faces numerous climate related constraints that entail development and dissemination of wheat germplasms with yield stabilizing traits under climate related challenges such as frost, drought, and yellow rust. The adoption of the germplasms will however depend on the effective demand of wheat growers. This study investigates the preferences and willingness to pay (WTP) for frost and yellow rust resistance, grain yield, grain color, plant height, and length of maturity traits of wheat in Ethiopia. A choice experiment method was used to generate 8181 observations from a random sample of 303 smallholder farm households. We report mean WTP values, preference heterogeneity and attribute non-attendance patterns based on different formulations of the mixed logit model. The results revealed that farmers are willing to pay for yellow rust resistance, frost resistance, increase in grain yield, and white grain color (cf. brown). Farmers showed disinterest in increase in length of maturity and black grain color (cf. brown). Farmers have high WTP for yellow rust resistance and frost resistance traits, which is nearly 10 times the value they are willing to pay for increase in grain yield of 100 kg per hectare. Similarly, farmers are willing to pay for harvesting wheat yield a month earlier a price four times the value they attach to increase in grain yield of 100 kg per hectare. The weight farmers attach to climate related traits of wheat show the importance farmers implicitly give to the climatic factors they must consider in their wheat production. Therefore, carefully developed wheat varieties would improve the effectiveness of the climate change adaptation strategies of smallholder farmers.

Combining ability studies on terminal heat tolerance in wheat (Triticum aestivum L.) under late sown irrigated condition using Line X Tester analysis

The present investigation entitled “Combining ability studies on terminal heat tolerance in wheat (Triticum aestivum L.) under late sown irrigated condition using Line X Tester design” was carried out during rabi 2017-18 and 2018-19 at the All India Co-ordinated Wheat and Barley Improvement Project, B.T.C. College of Agriculture and Research Station (IGKV), Bilaspur (C.G.). The experiment was conducted in RBD involving six lines, three testers and 18 F1s hybrids of wheat with two replications for study of character associated with yield and yield contributing traits. The analysis indicated that variance due to treatments was highly significant for all the characters under studied. All the characters except spike weight were highly significant. GCA, SCA and additive effect was found highest for character of harvest index. Among the lines, CG 1015 (Chhattisgarh Gehu)-04 was found good general combining ability (GCA) effect for the character of peduncle length, spike length, number of seed per plant and biological yield per plant. MP 3336 was found good GCA effect for chlorophyll reflection index, harvest index and number of tillers per plant. HD 2285 was found good GCA effect for days to maturity, 1000 seed weight and canopy temperature depreciation. Among the testers, Halna was good GCA effect for the character of days to 50% flowering, days to maturity and spike length. PHSL 10 was good GCA effect for number of tillers per plant, spike weight, seed yield per plant and harvest index. Among the crosses, CG 1015 (Chhattisgarh Gehu-04) X HUW 661 was good specific combining ability (SCA) effect for seed yield per plant. MP 3336 X PHSL 10 was good SCA effect for number of spikelet per spike and number of seed per plant. HD 2932 X Halna was good SCA effect for spike weight and 1000 seed weight and crosses HD 2864 X Halna was good SCA effect for the character of canopy temperature depreciation and biological yield per plant.

Age, growth and reproduction of the golden grey mullet, Chelon auratus (Risso, 1810) in the Golden Horn Estuary, Istanbul

AbstractAge, growth and reproduction biology of the golden grey mullet, Chelon auratus (Risso, 1810) have been studied in the Istanbul Golden Horn area. Fish length ranged from 13.4–46.8 cm, and age from 1–10 years, respectively. The sex ratio (female:male) was 1:1.08. The length-weight relationship was estimated as W = 0.0127L2.89, W = 0.0099L2.97 and W = 0.0156L2.82 for both sexes combined, females and males, respectively. The von Bertalanffy growth equation parameters were: L∞ = 57.52 cm, K = 0.1 year−1, t0 = −2.24 year for pooled data. The gonadosomatic index (GSI) values indicated the major spawning period was between August and November, and the minor spawning peak between March and April. The highest GSI values were observed in September. The length and age of sexual maturity were estimated as 26.2 cm and 4 years for males and 24.1 cm and 3 years for females.

Forward and inverse methods for extracting climate and diet information from stable isotope profiles in proboscidean molars

Intratooth stable isotope profiles in enamel provide time series of dietary and environmental information that if correctly interpreted, serve as archives of seasonal variability in past environments. A major challenge in interpreting these profiles arises from time averaging imparted by enamel mineralization and developmental geometry, whereby the primary (δ13C or δ18O) input signal is attenuated and shifted, which can potentially lead to incorrect interpretations of the magnitude or frequency of seasonal variability. Several forward and inverse models have been developed to reconstruct the primary input signal from intratooth profiles in continuously growing teeth. Here the models developed by Passey and Cerling (2002) and Passey et al. (2005) are extended to molars of Elephantinae, which grow over a long but finite interval of time. Proboscidean molars are particularly attractive for intratooth profiles because they may contain a decade or more of information and they are often well preserved in the fossil record because of their thick enamel and large size.Forward model parameters are established using histological analysis of molar thin sections of extant African elephants (Loxodonta africana) and a mammoth (Mammuthus columbi) and by micro-CT analysis of L. africana molar plates. The density of immature enamel is about 65% of the final density of mature enamel. The appositional length varies from approximately 35 to 55 mm, and the maturation length is about 70 mm. Histological methods are used to determine crown formation time (CFT) in elephant and mammoth molar plates. CFT for the elephant and mammoth molar plates studied in thin section are about 5–6 years and 11 years, which translate to mean growth rates of about 21 mm/year and 16 mm/year, respectively.Coeval molar and tusk profiles from a zoo elephant are compared. The tusk isotope profile serves as a proxy for the primary input signal, and thus provides an opportunity to evaluate the forward and inverse models. The results from the zoo elephant profiles demonstrate that the inverse model accurately reconstructs the amplitude and overall structure of the primary input signal. Inverse model results of mammoth molar profiles show double the range of δ13C in measured enamel profiles. Inversion model results illustrate that improved reconstruction of the primary input signal can lead to more accurate interpretations of the seasonal variability of diet and body water and by extension, vegetation and precipitation in past environments.

Perceived Risk and Willingness to Provide Loan to Smallholder Farmers in Ghana

ABSTRACT In this article, we investigate whether lending institutions perceive smallholder (individual) farmers as riskier borrowers than farm cooperatives. Our research results show that individual farmers in Ghana are less likely to be successful in obtaining credit than cooperative farmers, because they are perceived to be riskier borrowers. In addition, results show that the willingness of lending institutions to provide loans is higher for those farmers who are associated with cooperative societies. This suggests that individual farmers can increase their odds of securing loans by joining a cooperative society. Empirical results also support the hypothesis that the interest rate is a significant predictor of the willingness to loan bias among lending institutions. In addition, our results indicate that higher interest rates are associated with increased loan risk. However, when interest rate is higher, longer loan maturity can dampen the effect of interest rate. In other words, an increase in loan maturity length reduces the effect of interest rate on the loan risk. These research results have important policy implications for the welfare of smallholder farmers in developing economies as lack of financing has a significant impact on smallholder farmer productivity.

Interannual variability of distribution, abundance and population dynamics of the smooth hammerhead Sphyrna zygaena (Linnaeus, 1758) in the central‐southeast Pacific Ocean

This study provides information on the population dynamics of the smooth hammerhead shark Sphyrna zygaena in the central-southeast Pacific Ocean. The samples were obtained from artisanal fisheries from 2008 to 2013 to analyse cohorts, growth, mortality, abundance and recruitment using methods based on length and relative age and an inference multi-model. According to the von Bertalanffy growth model, the results indicated that the species showed from three to seven cohorts annually and slow growth (Wi = 57.20%): L∞ = 292.86 cm, K = 0.141 per year and t0 = -2.26. Length of sexual maturity was 239.30 and 209.10 cm at first capture; the average natural mortality value was 0.231 per year, by fishing 0.051 per year with a total mortality of 0.26 1 per year and exploitation rate of 0.15. Interannual variability was recorded in biomass with an average of 7367.24 tonnes, as well as a spatial permanence pattern. The results suggest that the La Niña event biologically favours the population in the area. The information from this study is essential for better understanding the species population and serves as a basis for future actions of management and conservation of S. zygaena.

Onset of Puberty: Mother Knows Best

Several strategies have been proposed to determine onset of puberty without examination by a trained professional. This study sought to evaluate a novel approach to determine onset of puberty in girls. This study used the Cincinnati cohort of the Breast Cancer and the Environment Research Program. Girls were recruited at 6-7years of age and followed every 6months in the initial 6years, and annually thereafter. Breast maturation and foot length were performed at each visit by health professionals certified in those methods. Mothers were asked to provide the age at which they believed that their daughter's shoe size had increased more rapidly. These analyses include 252 participants. Age at increase in shoe size was correlated to age at onset of puberty (r=0.21) and increase in foot length (r=0.24). The difference of reported age of increased shoe size was 0.46years before breast development. Reported increase in shoe size occurred somewhat earlier and was significantly correlated to age of breast development. These preliminary results suggest that mother's report of increase in shoe size appear to be as accurate as reports of other indirect methods of determining onset of puberty, such as self- or maternal estimates of breast development.

Predication of grain yield of rice using statistical model in Chhattisgarh plains

Rice is the chief agricultural product and one of the primary food sources for this reason, it is of pivotal importance for worldwide economy and development. Rice production in the Chhattisgarh is influenced by heat stress due to late sowing for optimization of yield, sowing at the appropriate time to fit the cultivar maturity length. The Statistical model was used to determine to assess the production potential for Raipur districts under varieties Mahamaya. The data analysis by SPSS and MS-Excel, it was found to be the most significant parameter for yield prediction of rice. Maximum temperatures for different decade are found predictors for the final yield in the end. Through SPSS model a simple linear equation has been determined for rice yield prediction in the area. With the help of weekly weather data, we find out correlation coefficient. On the basis of the identified significant weather parameters as independent variables and long term data of grain yield of Mahamaya variety, regression equation has developed. The equation the observed and predicted grain yields and significant results were drawn. The accuracy rate remained generally above 95% in experiment and present analysis of validation of regression model indicates only once in 2016-2017 this remained 96.7% or error is 3.3% during the last 10 years period. The prediction values are very close to the actual values of yield.

Storage length interacts with maturity to affect nutrient availability in unprocessed flint corn silage

Our objective was to determine the effects of maturity and storage length on the fermentation pattern, ruminal disappearance of nutrients, and recovery of digestible nutrients in flint corn (Zea mays L.) silage harvested with a pull-type machine without a kernel processor. Corn plants were harvested at 300 g kg−1 DM (low dry matter, LDM) or 400 g kg−1 DM (high dry matter, HDM) and stored for 0, 7, 14, 30, 60, 90, 120, and 180 d in laboratory silos. [...]