Cumulative Changes Research Articles

Fatigue Performance of Concrete–Polyurethane Composite Materials under Compression

Polyurethane grouting technology has been applied in the maintenance and reinforcement of transportation infrastructure such as airports, expressways, and high-speed railways. For rigid pavements with voids underneath concrete slabs, it can make a quick and efficient fix. However, polyurethane grouting materials applied underneath slabs for base enhancement are subjected to cyclic compressive loading from traffic, so their fatigue performance is critical in the concrete–polyurethane composite structure. There have not been many studies of this aspect. This paper investigated the influence of several key design factors, including grout thickness, grout density, and void shape, on the stress–strain and fatigue performance of the concrete–polyurethane composite structure. Laboratory compressive tests were conducted at various stress levels following a four-factor, three-level orthogonal experiment design. The results showed that the strain response of composite specimens under stress-controlled cyclic loading may be divided into three stages: an initial stage in which the cumulative strain changes little with the number of load repetitions, a second stage in which the cumulative strain increases steadily with the number of load repetitions, and a third stage in which the cumulative strain increases rapidly with the number of load repetitions. The third stage represents the occurrence of fatigue failure. The rank of the influences of the four factors on fatigue performance is, from high to low, grout thickness, stress ratio, void shape, and grout density.

Naturalistic Stress Hormone Levels Drive Cumulative Epigenomic Changes along the Cellular Lifespan.

Environmental stress is ubiquitous in modern societies and can exert a profound and cumulative impact on cell function and health phenotypes. This impact is thought to be in large part mediated by the action of glucocorticoid stress hormones, primarily cortisol in humans. While the underlying molecular mechanisms are unclear, epigenetics—the chemical changes that regulate genomic function without altering the genetic code—has emerged as a key link between environmental exposures and phenotypic outcomes. The present study assessed genome-wide DNA (CpG) methylation, one of the key epigenetic mechanisms, at three timepoints during prolonged (51-day) exposure of cultured human fibroblasts to naturalistic cortisol levels, which can be reached in human tissues during in vivo stress. The findings support a spatiotemporal model of profound and widespread stress hormone-driven methylomic changes that emerge at selected CpG sites, are more likely to spread to nearby located CpGs, and quantitatively accrue at open sea, glucocorticoid receptor binding, and chromatin-accessible sites. Taken together, these findings provide novel insights into how prolonged stress may impact the epigenome, with potentially important implications for stress-related phenotypes.

Target-Specific Sandwich Technique: Facial rejuvenation leveraging CPM technology.

Injectable rejuvenation treatments used in Caucasians might not always suit Asians as the visible signs of aging manifest differently, underscoring a need for Asian-specific strategies that correct underlying structural deficiencies and cumulative age-related changes. The presented Target-Specific Sandwich Technique (TSST) aims to simultaneously restore, rejuvenate, and enhance faces through the distribution of minute amounts of different fillers with different rheologies, using a minimal number of entry points in strategic facial areas and different soft tissue layers in Asians. A total of 14 patients underwent the presented TSST and were subsequently assessed for satisfaction with the treatment and the outcome of the treatment. With 3cc of fillers, patients experienced a rejuvenated appearance with brow support, brow ridge softening, less severe nasolabial folds, and corrected tear trough hollows. Fillers in the lateral canthal and mandibular angles lifted mouth corners, improved submandibular jowls, and defined the lower face. Although the prejowl sulcus received minimal filler, it appeared subtler, relaxed, and had fewer lines visible while smiling. Overall, patients appeared less tense, rejuvenated, and had improved light reflection and firmer skin. These were due to tissues being supported upward and laterally by fillers in areas of bone resorption-induced volume loss.

Global Induced Stress Field From Large Earthquakes Since 1900 and Chained Earthquake Occurrence

AbstractMegathrust earthquake occurrence is dependent on the physical properties and stress environments of convergent plate boundaries. Local and regional earthquakes may modulate the stress environment fractionally that affects the nucleation of next earthquakes. This study investigates the influence of precedent earthquakes on the induction of forthcoming earthquakes around the circum‐Pacific plate boundaries. We assess the global stress perturbation induced by 1,636 earthquakes combining 1,457 earthquakes with moment magnitudes greater than or equal to7.0 and 179 earthquakes with moment magnitudes6.4–6.9 in 1900–2020. We stack the induced Coulomb stress changes for optimally oriented reverse faults. The circum‐Pacific region is divided by eight subregions. The cumulative Coulomb stress changes reach up to the order of tens to hundreds of bar at the convergent plate boundaries. Descendant large earthquakes dominantly occurred in the regions with large lateral gradients of cumulative Coulomb stress changes induced by precedent earthquakes. The cumulative Coulomb stress changes for 120 years are comparable among subduction zones. The seismicity in subduction zones may depend on the strength of the stress field as well as the lateral gradient in the stress field. The instability and inhomogeneity in stress fields may play a major role in the nucleation of megathrust earthquakes.

Powerful detection of polygenic selection and evidence of environmental adaptation in US beef cattle.

Selection on complex traits can rapidly drive evolution, especially in stressful environments. This polygenic selection does not leave intense sweep signatures on the genome, rather many loci experience small allele frequency shifts, resulting in large cumulative phenotypic changes. Directional selection and local adaptation are changing populations; but, identifying loci underlying polygenic or environmental selection has been difficult. We use genomic data on tens of thousands of cattle from three populations, distributed over time and landscapes, in linear mixed models with novel dependent variables to map signatures of selection on complex traits and local adaptation. We identify 207 genomic loci associated with an animal’s birth date, representing ongoing selection for monogenic and polygenic traits. Additionally, hundreds of additional loci are associated with continuous and discrete environments, providing evidence for historical local adaptation. These candidate loci highlight the nervous system’s possible role in local adaptation. While advanced technologies have increased the rate of directional selection in cattle, it has likely been at the expense of historically generated local adaptation, which is especially problematic in changing climates. When applied to large, diverse cattle datasets, these selection mapping methods provide an insight into how selection on complex traits continually shapes the genome. Further, understanding the genomic loci implicated in adaptation may help us breed more adapted and efficient cattle, and begin to understand the basis for mammalian adaptation, especially in changing climates. These selection mapping approaches help clarify selective forces and loci in evolutionary, model, and agricultural contexts.

Bio‐mediated soil improvement: An introspection into processes, materials, characterization and applications

AbstractFor a long time in the practice of geotechnical engineering, soil has been viewed as an inert material, comprising only inorganic phases. However, microorganisms including bacteria, archaea and eukaryotes are ubiquitous in soil and have the capacity and capability to alter bio‐geochemical processes in the local soil environment. The cumulative changes could consequently modify the physical, mechanical, conductive and chemical properties of the bulk soil matrix. In recent years, the topic of bio‐mediated geotechnics has gained momentum in the scientific literature. It involves the manipulation of various bio‐geochemical soil processes to improve soil engineering performance. In particular, the process of microbial‐induced calcium carbonate precipitation (MICP) has received the most attention for its superior performance for soil improvement. The present work aims to shape a comprehensive understanding of recent developments in bio‐mediated geotechnics, with a focus on MICP. Referring to around one hundred studies published over the past five years, this review focuses on popular and alternative MICP processes, innovative raw materials and additives for MICP, emerging tools and testing methodologies for characterizing MICP at multi‐scale, and applications in emerging and/or unconventional geotechnical fields.

Analysis of the dynamic air conditioning loads, fuel consumption and emissions of heavy-duty trucks with different glazing and paint optical properties

The European transportation sector employs 10 million people and accounts for 4.6% of the European Union GDP. Due to climate change, this workforce is increasingly affected by high temperatures and radiant loads, particularly during summer. They rely on air conditioning (AC) to minimize heat inside the truck cabins, increasing fuel consumption and tailpipe emissions. Because sustainable transportation is crucial for climate change mitigation, we developed a numerical investigation on the dynamic thermal exchanges of cabins of heavy-duty trucks in realistic conditions of a summer workday, to quantify the potential impact of interventions in the glazing and paint optical properties, over the truck AC loads. We observed that the changes in air temperature and solar irradiation throughout the workday imply substantial variations in the truck’s AC loads and, consequently, in its fuel consumption and tailpipe emissions. Furthermore, windshields and side windows with transmissivity of 0.33 instead of typical 0.79 and 0.84, respectively, can reduce AC loads by up to 16%. External paints with reflectivity of 0.70 instead of 0.04 can reduce the AC loads by up to 30%, whereas cumulative changes to glazing and paint can reduce the AC load by up to 40%. These interventions can lower fuel consumption and emissions by up to 0.4%. These results show that important improvements in fuel efficiency and tailpipe emissions are possible, if the research community, policy makers and industry stakeholders successfully promote the adaptation of the European transportation fleet.

Expression of Parkin, APC, APE1, and Bcl-xL in Colorectal Polyps.

Colorectal cancer can develop through molecular, chromosomal, and epigenetic cumulative changes that transform the normal intestinal epithelium into the colorectal polyps, called conventional adenomas (CAs) or serrated polyps (SPs), recognized as precursors of invasive colorectal neoplasia. These benign lesions need to explore the morphology, histological diagnosis, and biomarkers profile to accurately characterize lesions with potential for evolution to cancer. This study aimed to correlate the immunohistochemical expression of Parkin and Adenomatous Polyposis Coli (APC; tumor suppressors), Human Apurinic/Apyrimidinic endonuclease 1 (APE1), and B-cell lymphoma-extra-large (Bcl-xL; oncogenic proteins) in sporadic colorectal polyps with clinical, endoscopic, and diagnostic data. Immunohistochemical analysis was performed on tissue microarray samples of 306 polyps. Based on the Allred score, the expressions were graduated in the cytoplasm and nucleus of superficial and cryptic cells. There was higher Parkin nuclear expression (p=0.006 and 0.010) and APC cytoplasmic expression in cryptic cells (p<0.001) in SPs. CAs, APE1 (p<0.001) and Bcl-xL (p<0.001) were more expressed in the nuclei and cytoplasms, respectively. These results are related to the biological role proposed for these proteins in cellular functions. They can contribute to the diagnosis criteria for polyps and improve the knowledge of biomarkers that could predict cancer development.

Basal ganglia: Bursting with song

The songs of mature zebra finches are notoriously repetitious, or 'crystallized'. Despite this stability, new work reveals that chronic pharmacologically driven bursting of cortical inputs to the basal ganglia can drive cumulative and lasting changes to multiple vocal features, including phenomena reminiscent of human stuttering.

Did Wastewater Disposal Drive the Longest Seismic Swarm Triggered by Fluid Manipulations? Lacq, France, 1969–2016

ABSTRACT The activation of tectonics and anthropogenic swarms in time and space and size remains challenging for seismologists. One remarkably long swarm is the Lacq swarm. It has been ongoing since 1969 and is located in a compound oil–gas field with a complex fluid manipulation history. Based on the overlap between the volumes where poroelastic model predicts stresses buildup and those where earthquakes occur, gas reservoir depletion was proposed to control the Lacq seismic swarm. The 2016 Mw 3.9, the largest event on the site, is located within a few kilometers downward the deep injection well. It questions the possible interactions between the 1955–2016 wastewater injections and the Lacq seismicity. Revisiting 60 yr of fluid manipulation history and seismicity indicates that the impacts of the wastewater injections on the Lacq seismicity were previously underevaluated. The main lines of evidence toward a wastewater injection cause are (1) cumulative injected volume enough in 1969 to trigger Mw 3 events, onset of Lacq seismicity; (2) 1976 injection below the gas reservoir occurs only a few years before the sharp increase in seismicity. It matches the onset of deep seismicity (below the gas reservoir, at the injection depth); (3) the (2007–2010) 2–3 folds increase in injection rate precedes 2013, 2016 top largest events; and (4) 75% of the 2013–2016 events cluster within 4–8 km depths, that is, close to and downward the 4.5 km deep injection well. As quantified by changepoint analysis, our results suggest that timely overlaps between injection operations and seismicity patterns are as decisive as extraction operations to control the Lacq seismicity. The seismicity onset is contemporary to cumulative stress changes (induced by depletion and injection operations) in the 0.1–1 MPa range. The interrelation between injection and extraction is the most probable cause of the Lacq seismicity onset and is sustenance over time. The injected volume–largest magnitude pair for Lacq field is in the same range (90% confidence level) than wastewater volume–magnitude pairs reported worldwide, in a wide variety of tectonic settings.

Plasticity of stereotyped birdsong driven by chronic manipulation of cortical-basal ganglia activity

Cortical-basal ganglia (CBG) circuits are critical for motor learning and performance, and are a major site of pathology. In songbirds, a CBG circuit regulates moment-by-moment variability in song and also enables song plasticity. Studies have shown that variable burst firing in LMAN, the output nucleus of this CBG circuit, actively drives acute song variability, but whether and how LMAN drives long-lasting changes in song remains unclear. Here, we ask whether chronic pharmacological augmentation of LMAN bursting is sufficient to drive plasticity in birds singing stereotyped songs. We show that altered LMAN activity drives cumulative changes in acoustic structure, timing, and sequencing over multiple days, and induces repetitions and silent pauses reminiscent of human stuttering. Changes persisted when LMAN was subsequently inactivated, indicating plasticity in song motor regions. Following cessation of pharmacological treatment, acoustic features and song sequence gradually recovered to their baseline values over a period of days to weeks. Together, our findings show that augmented bursting in CBG circuitry drives plasticity in well-learned motor skills, and may inform treatments for basal ganglia movement disorders.

Daily increasing or decreasing photoperiod affects stress resistance and life history traits in four Drosophila species

Photoperiod is one of the most reliable seasonal cues that organisms can use to prepare for upcoming environmental changes. Evidence suggests that exposure to different photoperiod can activate plastic responses in stress resistance traits, while there is limited evidence on the plastic response induced by daily progressive cumulative changes in photoperiod. In this study, we assayed the effect of within generation daily uni-directional and cumulative changes in photoperiod on stress resistance and life history traits in four Drosophila species. We predicted that daily increasing photoperiod, mimicking upcoming summer conditions, should lead to an increase in heat resistance and establish trade-offs with other fitness related traits. On the other hand, we predicted that daily decreasing photoperiod should reflect upcoming winter conditions leading to an increase in cold resistance. We found that within genreation changes in photoperiod had a significant effect on life history and stress resistance traits in the four Drosophila species. The observed response was different across species, with D. melanogaster showing five out of six studied traits affected, while in D. mercatorum only one trait was significantly affected. The exposure to changing photoperiod led to an increased upper thermal resistance in D. melanogaster and D. mercatorum and a decreased lower thermal resistance in D. melanogaster and D. simulans, as well as a decreased starvation and desiccation resistance in D. virilis. The developmental time was shorter when flies were exposed to the two photoperiod regimes compared to constant day length control in D. melanogaster and D. simulans. A limited effect was observed on egg-to-adult-viability and desiccation resistance. The results of this study show that daily change in photoperiod induced a plastic response in different traits of drosophilids, suggesting that this environmental parameter needs to be carefully considered in evolutionary studies.

Evolutionary Analysis of Pre-S/S Mutations in HBeAg-Negative Chronic Hepatitis B With HBsAg < 100 IU/ml.

Background: Hepatitis B surface antigen (HBsAg) and viral load are important clinical indicators for antiviral therapy. Few studies have evaluated viral sequence biomarkers predicting the risk of hepatocellular carcinoma (HCC) in the stage, which show a low serological response (HBsAg < 100 IU/ml) and high viral levels (HBV DNA > 2,000 IU/ml). This study aims to determine the trend of the biological prevalence within the pre-S/S regions of special model of inactive CHB infection.Methods: We used Sanger sequencing, quantitative HBV serology (HBeAg and HBsAg), and liver function index to identify whether HBV genome sequences are associated with long-term risk of further HCC progression in special inactive CHB infection.Results: HBV sequencing analysis of 28 CHB patients with special infectious pattern showed higher genetic diversity among four opening reading frames (ORFs) (p < 0.001). However, dN/dS ratios of HBsAg and pre-C/C regions in the experimental group showed no significantly different from those in the HCC group (p = 0.06), while significantly lower in polymerase and HBxAg regions of the experimental group (p < 0.001). In addition, seven positively selected sites were identified in pre-S1, five in pre-S2, and four in S, in which five sites (128H/135Q/135R/139L/141P) were among “α” determinant.Conclusions: These mutations in the pre-S/S region might be associated with the HCC phenotype of low HBsAg expression, with the P region possibly impacting high viral loads. Increased viral diversity across the HBV genome is also associated with low levels of HBsAg. The cumulative evolutionary changes in the HBV pre-S/S regions shows that facilitate immune evasion should be monitored individually. Due to the similarity of evolutionary characteristics in HCC, low serological responses and high viremia may be associated with the risk of further disease progression.

Landscape dynamics specific features of the river Volga estuarine natural systems particularlong inundable territories

Multi-method landscape-ecological researches results on stationary parts in the river Volga delta, transformed to rank of natural sanctuary in the period of 1978-2016 are presented in this work. The main landscape dynamics tendencies are discovered, natural and anthropogenous factors of soil and vegetation cover are estimated for peculiar long inundable territories: water-soluble salts cationicanionic analysis and their migration specific features and accumulation in dependence of the limited natural and anthropogenous factors changes for long inundable soil cover for forty years period; integrated effect of meteorological, hydrological, adaphic and anthropogenous factors cumulative changes on different years fluctuations and seral vegetational change for vegetation was revealed. Multi-year researches results show that the main factors, defining content and highly soluble salts radial migration in soils, also vegetation productivity and its species composition are hydrological regime (most of all – spring-summer floodings character) and territory climatic specific features. However, it is necessary to take into account local secondary effects influence, which can have an effective refracted impact on ambient background signals besides the main primary factors effect.

Indoor simulation test research on cumulative longitudinal displacement of rail based on force and displacement sensors data collection.

The train sometimes needs to brake frequently on the turnout, although the braking force does not exceed the limit resistance of fastener, cumulative displacement of rail occurs because of the long-term effect of the train brakes, thus, the relationship between the cumulative displacement of rail and the number of train braking actions should be explored. Aiming at the spring bar type III fastener, a 1:1 physical indoor simulation test was carried out, and an electromagnetic relay device was used to simulate the train load, force, and displacement sensors for data collection. Then a single load no more than the maximum resistance of fastener was applied to the rail end to explore the relationship between the number of loads and the rail cumulative deformation. The rail longitudinal cumulative displacement changes linearly in positive correlation with the number of load actions, and increases faster when the number of load actions is small. As the number of repeated loads increases, the above-mentioned relationship approximately and credibly obeys the power function distribution. Repeatedly applying load no more than the maximum longitudinal resistance of fastener to the rail, the existence of the rail cumulative displacement caused by frequent train braking can be demonstrated, and the relationship curve between the rail displacement and the number of loads can be obtained. Applying the fitting formula, the rail displacement after a specific number of loading times can be attained, and then referring to specific codes, we can determine whether it will exceed the safety limit.

Inflation-Adjusted Medicare Reimbursement for Revision Hip Arthroplasty

Background: Investigations into reimbursement trends for primary and revision arthroplasty procedures have demonstrated a steady decline over the past several years. Revision total hip arthroplasty (rTHA) due to infection (rTHA-I) has been associated with higher resource utilization and complexity, but long-term inflation-adjusted data have yet to be compared between rTHA-I and rTHA due to aseptic complications (rTHA-A). The present study was performed to analyze temporal reimbursement trends regarding rTHA-I procedures compared with those for rTHA-A procedures. Methods: The Centers for Medicare &amp; Medicaid Services (CMS) Physician Fee Schedule Look-Up Tool was used to extract Medicare reimbursements associated with 1-stage and 2-stage rTHA-I as well as 1-stage rTHA-A procedures from 2002 to 2019. Current Procedural Terminology (CPT) codes for rTHA were grouped according to the American Academy of Orthopaedic Surgeons coding reference guide. Monetary values were adjusted for inflation using the consumer price index (U.S. Bureau of Labor Statistics; reported as 2019 U.S. dollars) and used to calculate the cumulative and average annual percent changes in reimbursement. Results: Following inflation adjustment, the physician fee reimbursement for rTHA-A decreased by a mean [and standard deviation] of 27.26% ± 3.57% (from $2,209.11 in 2002 to $1,603.20 in 2019) for femoral component revision, 27.41% ± 3.57% (from $2,130.55 to $1,542.91) for acetabular component revision, and 27.50% ± 2.56% (from $2,775.53 to $2,007.61) for both-component revision. Similarly, for a 2-stage rTHA-I, the mean reimbursement declined by 18.74% ± 3.87% (from $2,063.36 in 2002 to $1,673.36 in 2019) and 24.45% ± 3.69% (from $2,328.79 to $1,755.45) for the explantation and reimplantation stages, respectively. The total decline in physician fee reimbursement for rTHA-I ($1,020.64 ± $233.72) was significantly greater than that for rTHA-A ($580.72 ± $107.22; p &lt; 0.00001). Conclusions: Our study demonstrated a consistent devaluation of both rTHA-I and rTHA-A procedures from 2002 to 2019, with a larger deficit seen for rTHA-I. A continuation of this trend could create substantial disincentives for physicians to perform such procedures and limit access to care at the population level. Level of Evidence: Economic and Decision Analysis Level IV. See Instructions for Authors for a complete description of levels of evidence.

Nitrogen Losses and Potential Mitigation Strategies for a Sustainable Agroecosystem

Nitrogen (N) in the agricultural production system influences many aspects of agroecosystems and several critical ecosystem services widely depend on the N availability in the soil. Cumulative changes in regional ecosystem services may lead to global environmental changes. Thus, the soil N status in agriculture is of critical importance to strategize its most efficient use. Nitrogen is also one of the most susceptible macronutrients to environmental loss, such as ammonia volatilization (NH3), nitrous oxide (N2O) emissions, nitrate leaching (NO3), etc. Any form of N losses from agricultural systems can be major limitations for crop production, soil sustainability, and environmental safeguard. There is a need to focus on mitigation strategies to minimize global N pollution and implement agricultural management practices that encourage regenerative and sustainable agriculture. In this review, we identified the avenues of N loss into the environment caused by current agronomic practices and discussed the potential practices that can be adapted to prevent this N loss in production agriculture. This review also explored the N status in agriculture during the COVID-19 pandemic and the existing knowledge gaps and questions that need to be addressed.

Histone H3 lysine 4 trimethylation in sperm is transmitted to the embryo and associated with diet-induced phenotypes in the offspring.

A father's lifestyle impacts offspring health; yet, the underlying molecular mechanisms remain elusive. We hypothesized that a diet that changes methyl donor availability will alter the sperm and embryo epigenomes to impact embryonic gene expression and development. Here, we demonstrate that a folate-deficient (FD) dietalters histone H3 lysine 4 trimethylation (H3K4me3) in sperm at developmental genes and putative enhancers. A subset of H3K4me3 alterations in sperm are retained in the pre-implantation embryo and associated with deregulated embryonic gene expression. Using a genetic mouse model in which sires have pre-existing altered H3K4me2/3 in sperm, we show that a FD diet exacerbates alterations in sperm H3K4me3 and embryonic gene expression, leading to an increase in developmental defect severity. These findings imply that paternal H3K4me3 is transmitted to the embryo and influences gene expression and development. It further suggests that epigenetic errors can accumulate in sperm to worsen offspring developmental outcomes.

The Annual Cycle of Upper-Ocean Potential Vorticity and Its Relationship to Submesoscale Instabilities

AbstractThe evolution of upper-ocean potential vorticity (PV) over a full year in a typical midocean area of the northeast Atlantic is examined using submesoscale- and mesoscale-resolving hydrographic and velocity measurements from a mooring array. A PV budget framework is applied to quantitatively document the competing physical processes responsible for deepening and shoaling the mixed layer. The observations reveal a distinct seasonal cycle in upper-ocean PV, characterized by frequent occurrences of negative PV within deep (up to about 350 m) mixed layers from winter to mid-spring, and positive PV beneath shallow (mostly less than 50 m) mixed layers during the remainder of the year. The cumulative positive and negative subinertial changes in the mixed layer depth, which are largely unaccounted for by advective contributions, exceed the deepest mixed layer by one order of magnitude, suggesting that mixed layer depth is shaped by the competing effects of destratifying and restratifying processes. Deep mixed layers are attributed to persistent atmospheric cooling from winter to mid-spring, which triggers gravitational instability leading to mixed layer deepening. However, on shorter time scales of days, conditions favorable to symmetric instability often occur as winds intermittently align with transient frontal flows. The ensuing submesoscale frontal instabilities are found to fundamentally alter upper-ocean turbulent convection, and limit the deepening of the mixed layer in the winter-to-mid-spring period. These results emphasize the key role of submesoscale frontal instabilities in determining the seasonal evolution of the mixed layer in the open ocean.

Live weight changes during lactation and its relationship with milk off-take and yield in West African Dwarf and Red Sokoto goats intensively managed within the humid zone of Nigeria

This study focused on changes in doe live weight during lactation in West African dwarf (WAD) and Red Sokoto (RS) goats intensively managed within the humid zone of South-western Nigeria. The data analysed was based on 202 weekly records. from 17 lactations of 8 WAD and 9 RS goats from year 2000-2002. Mean live weight for RS does (21.16+0.34 kg) was higher (P&lt;0.001) than the estimate (18.15+0.34 kg) for WAD does. Live weight decreased (P&gt;0.05) from parturition up to fourth week and increased (P&gt; 0.05) thereafter till the 12th week of lactation. There was no significant interaction between breed and week of lactation. Cumulative mean weight changes of 0.16+4119 kg for WAD and 0.38+0.22 kg for RS were not significantly different, Does had higher (P&lt;0.001) body weights during the late- wet and early-dry seasons than during late-thy and early-wet seasons.. Live weight increased .significantly (P&lt;0.001) with parity of doe, the trend being maintained with regards to cumulative weight change. Does that suckled male kids were less superior in body weights. This was reflected by a negative cumulative weight change. Live weight was positively con-elated with milk yield (rp = 0.24; P&lt;0.05,4 estimated at 270.61+13.48 ml and 281.98+ 13. 17 ml respectively for RS and WAD goats (P&gt;0.05). Corresponding values for milk off-take were (.14.09+3.64 and 16,45+3.56 ml; P&gt;0.05), Milk off-take was lowly correlated with live weight (rp= 0_06; P&gt;0.05) while its relationship with milk yield was positive and significant (rp= 0.40: P&lt;0.001).