Capacity For Use Research Articles

Synthesis and investigation of sulfonated poly(p-phenylene)-based ionomers with precisely controlled ion exchange capacity for use as polymer electrolyte membranes.

To achieve precise control of sulfonated polymer structures, a series of poly(p-phenylene)-based ionomers with well-controlled ion exchange capacities (IECs) were synthesised via a three-step technique: (1) preceding sulfonation of the monomer with a protecting group, (2) nickel(0) catalysed coupling polymerisation, and (3) cleavage of the protecting group of the polymers. 2,2-Dimethylpropyl-4-[4-(2,5-dichlorobenzoyl)phenoxy]benzenesulfonate (NS-DPBP) was synthesised as the preceding sulfonated monomer by treatment with chlorosulfuric acid and neopentyl alcohol. NS-DPBP was readily soluble in various organic solvents and stable during the nickel(0) catalysed coupling reaction. Sulfonated poly(4-phenoxybenzoyl-1,4-phenylene) (S-PPBP) homopolymer and seven types of random copolymers (S-PPBP-co-PPBP) with different IECs were obtained by varying the stoichiometry of NS-DPBP. The IECs and weight average molecular weights (Mws) of ionomers were in the range of 0.41–2.84 meq. g−1 and 143 000–465 000 g mol−1, respectively. The water uptake, proton conductivities, and water diffusion properties of ionomers exhibited a strong IEC dependence. Upon increasing the IEC of S-PPBP-co-PPBPs from 0.86 to 2.40 meq. g−1, the conductivities increased from 6.9 × 10−6 S cm−1 to 1.8 × 10−1 S cm−1 at 90% RH. S-PPBP and S-PPBP-co-PPBP (4 : 1) with IEC values >2.40 meq. g−1 exhibited fast water diffusion (1.6 × 10−11 to 8.0 × 10−10 m2 s−1), and were comparable to commercial perfluorosulfuric acid polymers. When fully hydrated, the maximum power density and the limiting current density of membrane electrode assemblies (MEAs) prepared with S-PPBP-co-PPBP (4 : 1) were 712 mW cm−2 and 1840 mA cm−2, respectively.

CAPACIDADE DE USO E APTIDÃO AGRÍCOLA DE UMA FAZENDA EM SÃO DOMINGOS DO ARAGUAIA (PA)/ Capacity of use and agricultural aptitude of a farm in São Domingos do Araguaia (PA)

A crescente utilização das terras, sem considerar suas potencialidades e limitações, acarreta à degradação ao solo. Para tanto se faz necessário que o uso da terra seja adequado às condições propiciadas pelos elementos físicos da paisagem. Este trabalho teve como objetivo analisar e classificar os solos da fazenda Cristalina no Município de São Domingos do Araguaia, PA, através da apresentação do mapeamento da Capacidade de Uso e da Aptidão Agrícola das Terras. Para isso foram construídos mapas, através do software ArcGIS, que espacializa as principais restrições nos dois sistemas de classificação de terras. A classificação das terras da fazenda Cristalina, PA para uso agrícola sofreu consideráveis limitações, a primeira se justifica pela própria localidade da propriedade. Esta fazenda se encontra em pleno Bioma Amazônia, por isto amparado por leis, precauções acerca de uso agrícola deverão ser tomadas respeitando-se o conceito da Amazônia Legal.

Изучение характера распределения осевой нагрузки по виткам резьбы планетарного роликовинтового механизма

The article considers the effect of axial load on the turns of the thread of the planetary roller-screw converter of rotational motion into translational one. For this purpose an experimental setup was made in which the nut lies end-face on the flat surface of the press, a screw is screwed into it. The force is applied to the screw through a ball to distribute the load uniformly. The design of the machine for compression measurement allows automatic recording the axial mutual movement of tested mechanism parts when the loading force changes. Contact and displacement occur when the loading force reaches 300 N. The results are obtained in the form of a "force – displacement" graph. In the course of the experiment, the influence of step error on the uniformity of the contacts of the turns of the mating parts of the planetary roller-screw mechanism was checked. The results of the experiment are analyzed, the influence of inaccuracy of manufacturing thread of planetary roller-screw mechanism parts on its capacity for use in feed drives of various machines is considered.

A profile of visitors to Brazil Amazon Protected Areas:

The purpose of this study was to develop a profile of visitors at two touristic settings and protected areas in the Brazilian Amazon Basin: Tapajós National Forest (Pará) and Anavilhanas National Park (Amazonas). An onsite survey was conducted across the two areas. The total of number of usable data points from the two areas of study used in this paper is 2512 surveys (1255 at Tapajós and 1257 at Anavilhanas). The data collected offers an important source of information for managers so that they may better understand the recreational needs and current capacity for use at both protected areas. One of the aims of this study was to gather data to understand the current flow of visitors in the Amazon by focusing on their specific characteristics. This type of information is crucial for managing public use and developing tourism in protected areas. The project team is grateful to the US Forest Service—International Programs (USFS—IP), US Agency for International Development (USAID), and the USDA National Institute of Food and Agriculture (NIFA) who made this study possible. The authors are also grateful to the Instituto Chico Mendes (ICMBio), Tapajós National Forest, Anavilhanas National Park team and local community members who have collected data and supported this research.

Brazilian sardinella ( Sardinella brasiliensis ) conservation by immersion in seawater added with sea salt and refrigerated on‐board

On‐board Brazilian sardinella (Sardinella brasiliensis) conservation system based on cooling in ice, but in recent years, fishing boats have been applying immersion in chilled brine as a storage system on‐board. This study evaluated this system concerning physicochemical quality (total volatile bases, pH, histamine, moisture) of the fish and cation concentrations. Offshore (on‐board) data were collected (total storage time, over time temperature, fish mass captured by bid, load capacity in use and available) to assess the efficiency and viability. The results showed that this system is useful in maintaining the physicochemical quality of the fish since the samples met the quality standards required by law. Data showed high levels of sodium in fish muscle, which are strongly influenced by the immersion time, suggesting the need for standardization of the method considering the risks associated with consumption of foods with high levels of sodium.

NaCl-template-assisted freeze-drying synthesis of 3D porous carbon-encapsulated V2O3 for lithium-ion battery anode

Vanadium trioxide material have attracted enormous attention recently, owing to their high theoretical capacity for use as anodes in lithium ion batteries. However, the unstable structure of V2O3 limits its practical application. It is challenge to develop a simple, scalable and economical technique to produce 3D porous carbon-based V2O3 materials with high structure stability. In this work, a facile NaCl template-assisted freeze-drying strategy was used to produce 3D porous carbon-encapsulated V2O3 (3D porous V2O3@C) composites with highly crystalline architecture, uniformly carbon-encapsulated V2O3 nanoparticles and interconnected conductive carbon networks. The resultant 3D porous V2O3@C anode exhibits significantly enhanced rate performance (797 mAh/g at 0.1 A/g, 715 mAh/g at 0.3 A/g, 658 mAh/g at 0.5 A/g, 598 mAh/g at 1 A/g, 480 mAh/g at 3 A/g and 426 mAh/g at 5 A/g) and long-term cycling stability (506 mAh/g at 5A/g after 2000 cycles). The present work suggests a scalable preparation of the 3D porous carbon-based V2O3 materials, which may be extended to preparing other 3D porous materials for potential applications in energy storage, catalysis and sensors.

Assessing the impact of introduced infrastructure at sea with cameras: A case study for spatial scale, time and statistical power

Detecting the effects of introduced artificial structures on the marine environment relies upon research and monitoring programs that can provide baseline data and the necessary statistical power to detect biological and/or ecological change over relevant spatial and temporal scales. Here we report on, and assess the use of, Baited Remote Underwater Video (BRUV) systems as a technique to monitor diversity, abundance and assemblage composition data to evaluate the effects of marine renewable energy infrastructure on mobile epi-benthic species. The results from our five-year study at a wave energy development facility demonstrate how annual natural variation (time) and survey design (spatial scale and power) are important factors in the ability to robustly detect change in common ecological metrics of benthic and bentho-pelagic ecosystems of the northeast Atlantic. BRUV systems demonstrate their capacity for use in temperate, high energy marine environments, but also how weather, logistical and technical issues require increased sampling effort to ensure statistical power to detect relevant change is achieved. These factors require consideration within environmental impact assessments if such survey methods are to identify and contribute towards the management of potential positive or negative effects on benthic systems.

Development of an innovative technology to segment luminal borders of intravascular ultrasound image sequences in a fully automated manner

Although intravascular ultrasound (IVUS) is the commonest intravascular imaging modality, it still is inefficient for clinical use as it requires laborious manual analysis. This study demonstrates the feasibility of a near real-time fully automated technology for accurate identification, detection, and quantification of luminal borders in intravascular images. This technology uses a combination of the novel approaches of a self-tuning engine, dynamic and static masking systems, radar-wise scan, and contour correction cycle method. The performance of the computer algorithm developed based on this technology was tested on a sequence of IVUS and True Vessel Characterization (TVC) images obtained from the left anterior descending (LAD) artery of 6 patients with coronary artery disease. The accuracy of the algorithm was evaluated by comparing luminal borders traced manually with those detected automatically. The processing time of the developed algorithm was also tested on a Dell laptop with an Intel Core i7-8750H Processor (4.1 GHz with 6 cores, 9 MB Cache). Linear regression and Bland-Altman analyses indicated high correlation between manual and automatic tracings (Y = 0.80 × X+1.70, R2 = 0.88 & 0.67 ± 1.31 (bias±SD)). Whereas analysis of 2000 IVUS images using one CPU core with a 30% load took 23.12 min, the same analysis using six CPU cores with 90% load took 1.0 min. The performance, accuracy, and speed of the presented state-of-the-art technology demonstrates its capacity for use in clinical settings.

Capacidade de uso da terra da sub-bacia do Córrego Maria Comprida usando Sistemas de Informações Geográficas

Agriculture is fundamental for the development of humanity; however, it is necessary to adjust land use planning in order to reconcile agricultural activities with proper soil management practices, thus reducing the impact on the environment. The study aimed to evaluate the land use capacity of the Córrego Maria Comprida-MG sub-basin, located in the Caratinga and Rio Doce river basins. The support of the Geographic Information System (GIS) was used for the framing of the lands according to the system of the capacity of use. The Number of Exceeding Classes (NCE) was evaluated in order to identify conflicts between land use and current land use. It was verified that the sub-basin presents approximately 60% of its land in class VI of the capacity of use and that about half of the study area is being used above its capacity, occupied mainly by pastures. The results proved its importance for planning the rational use of land in the Maria Comprida stream sub-basin.

A simple and reliable protocol for long-term culture of murine bone marrow stromal (mesenchymal) stem cells that retained their in vitro and in vivo stemness in long-term culture

BackgroundBone marrow derived stromal stem cells (BMSCs) are a clonogenic cell population that is characterized by self-renewal capacity and differentiation potential into osteoblasts, and other mesenchymal cell types. Mouse BMSCs (mBMSCs) are difficult to be cultured and propagated in vitro due to their replicative senescent phenotype, heterogeneity and high contamination with plastic adherent hematopoietic progenitors (HPCs). In this study, we described long-term culture of homogenous population of mBMSCs using simple and highly reproducible approach based on frequent subculturing (FS) at fixed split ratio in the presence of basic fibroblast growth factor (bFGF).ResultsCultured mBMSCs using this protocol (mBMSCs-FS) showed long-term survival in culture > 70 population doubling (PD) and retained their characteristic surface markers and differentiation capacity into osteoblast and adipocyte lineages. When compared to the clonal bone marrow-derived cell line ST2, mBMSCs-FS displayed more enhanced osteoblast differentiation potential and responsiveness to osteogenic factors including BMPs, IGF-1, PDGF, TGFβ1,3, FGF, cAMP, Wnt3a and VEGF. In addition, unlike ST2 cells, mBMSCs-FS maintained capacity to form ectopic bone and bone marrow stroma upon in vivo transplantation in immune-compromising mice, even at high PD levels. Interestingly, by applying the same FS + bFGF protocol, we succeeded to obtain long-term cultures of primary neonatal calvarial osteoprogenitor cells (OBs) that were cultured for more than 70 PD and maintained in vitro and in vivo osteoblast differentiation capacities.ConclusionsOur data provide a simple and reliable protocol for generating long-term cultures of mBMSCs and OBs with retained high in vitro and in vivo osteoblast differentiation capacities for use in pre-clinical and molecular mechanism studies.

Distributed Software Architecture for AGVs for Separation of Dynamic and Static Obstacles

The current trend towards mass customization confronts established mass production systems with specific challenges. In future production layouts will have to provide a high degree of flexibility and changeability in order to be able to respond to the demand for individualized mass products. This leads to a production network in which the work schedule of each product and thus the sequence of the individual production resources are flexibly arranged. A challenge in this scenario is the implementation of material transport between the machines. The use of mobile transport robots to realize a flexible connection of all material sources and sinks proves to be effective. However, the current design forms, as a monolithic AGV system or the use of flexible autonomous units, show specific weaknesses. The paper describes the research approach to establish an intralogistics service-based software architecture as an intralogistics execution system, which contains the elementary functions of a cross-platform use of mobile autonomous systems. One key application is to digitize the workspace of the mobile systems with a distributed system of infrastructural sensors. An embedded unit separates the scenario into static and dynamic obstacles. The method discussed also includes the aggregation of the images with static obstacles to a world model as a basis for global cross-platform routing. Thus, it is possible to include the static obstacles in an early phase of path planning. The researched architecture integrates a routing service, which offers a cross-platform map for each type of transport robots in use. The dynamic obstacles of the respective scenery are tracked directly by the embedded decentralized ceiling sensors. By combining the Hungarian method with a Kalman filter, the trajectory of the detected dynamic obstacles can be determined. Within the discussed method, this information is transmitted directly from the sensor units to the autonomous systems and allows the local path planner to avoid collisions. Within the implementation of both methods in an industrial demonstrator, the functionality of both services could be validated. The necessary real-time capability for a valid collision avoidance was not achieved due to the computing capacities in use.

Transferability of Research Findings: Lessons From the BCURE (Building Capacity for the Use of Research Evidence) Program for Implementing EBPM (Evidence-Based Policy Making) in Non-Western Countries

The DFID-funded BCURE (Building Capacity for Use of Research Evidence) Program has generated important research findings on the determinants for the demand of evidence use in six countries: Bangladesh, Kenya, Pakistan, Sierra Leone, South Africa and Zimbabwe. What is the relevance of these research findings on the capacity gap in public administration for other non-Western countries? The BCURE Program targeted interventions at the individual, interpersonal and organizational levels, and across three impact pathways, namely the ministry, across government, and Parliament. BCURE specified a detailed Theory of Change (ToC) and used the realist evaluation approach, and specified CIMOs (Context-Intervention-Mechanism-Output) to understand the contexts under which the mechanisms operate successfully. BCURE found three ways of working that were successful across the six countries. First, in the promotion of Evidence-Based Policy Making (EBPM), it is important to understand the politics. Second, the proponents of EBPM must build capacity at different levels of government. Third, the proponents must accompany change, and not impose it.

Differential Role of Hypothalamic AMPKα Isoforms in Fish: an Evolutive Perspective.

In mammals, hypothalamic AMP-activated protein kinase (AMPK) α1 and α2 isoforms mainly relate to regulation of thermogenesis/liver metabolism and food intake, respectively. Since both isoforms are present in fish, which do not thermoregulate, we assessed their role(s) in hypothalamus regarding control of food intake and energy homeostasis. Since many fish species are carnivorous and mostly mammals are omnivorous, assessing if the role of hypothalamic AMPK is different is also an open question. Using the rainbow trout as a fish model, we first observed that food deprivation for 5days did not significantly increase phosphorylation status of AMPKα in hypothalamus. Then, we administered adenoviral vectors that express dominant negative (DN) AMPKα1 or AMPKα2 isoforms. The inhibition of AMPKα2 (but not AMPKα1) led to decreased food intake. The central inhibition of AMPKα2 resulted in liver with decreased capacity of use and synthesis of glucose, lipids, and amino acids suggesting that a signal of nutrient abundance flows from hypothalamus to the liver, thus suggesting a role for central AMPKα2 in the regulation of peripheral metabolism in fishes. The central inhibition of AMPKα1 induced comparable changes in liver metabolism though at a lower extent. From an evolutionary point of view, it is of interest that the function of central AMPKα2 remained similar throughout the vertebrate lineage. In contrast, the function of central AMPKα1 in fish relates to modulation of liver metabolism whereas in mammals modulates not only liver metabolism but also brown adipose tissue and thermogenesis.

BIOTRANSFORMATION OF GINSENOSIDE Rb1 BY BACTERIAL CRUDE ENZYME OF Paenibacillus spp. strain E3 ISOLATED FROM VIETNAMESE GINSENG SOIL

In ginseng, minor ginsenosides were more effective pharmacological properties than major ginsenosides. Therefore, finding bacteria that can convert major ginsenosides has been paying attention. Ginsenoside Rb1 is one of major ginsenosides of ginseng and its biotransformation produces pharmacologically active compounds such as compound K. In this study, the isolation of bacterial strains from Vietnamese ginseng cultivated soil was carried out with the objective of evaluating their hydrolytic capacity for use in biotransformation of ginsenosides Rb1. In the screening of β-glucosidase producing bacteria, seven isolates exhibited black color zones on R2A agar medium containing esculine. Among seven isolates, strain E3 showed the highest ability biotransformation of ginsenosides Rb1 in Luria-Bertani broth. Therefore, strain E3 was selected for further research. Biotransformation of Rb1 was observed by using thin layer chromatography (TLC) and high performance liquid chromatography (HPLC) with ginsenoside standards for comparison. We determined the optimal conditions for biotransformation of ginsenoside Rb1 into the compound K of crude enzymes of strain E3 were at 30°C, pH 7,0 and 3 days. Ginsenoside Rb1 was converted into compound K via ginsenoside Rd and F2. The analyses of 16S rRNA gene and phylogenetic tree indicated that strain E3 was closely related to Paenibacillus terrigena with 99,4% identity and formed a discrete cluster with type strain Paenibacillus terrigena A35T with high bootstrap support (99%), supporting strain E3 belonging to the species Paenibacillus terrigena. Physiological characteristics also supported strain E3 belonging to the genus Peanibacillus. This is the first report of biotransformation of ginsenosides using bacterial strains isolated from Vietnamese ginseng cultivated soil in Vietnam. Based on our the obtained results, strain E3 could be applied for the preparation of ginsenoside compound K for use in the cosmetic and pharmaceutical industries.

Development of a fluorescence-based cellular apoptosis reporter

Evasion of apoptosis is a hallmark of human cancer, and a desired endpoint of many anticancer agents is the induction of cell death. With the heterogeneity of cancer becoming increasingly apparent, to understand drug mechanisms of action and identify combination therapies in cell populations, the development of tools to assess drug effects at the single cell level is a necessity for future preclinical drug development. Herein we describe the development of pCasFSwitch, a genetically encoded reporter construct designed to identify cells undergoing caspase-3 mediated apoptosis, by a translocation of a GFP signal from the cell membrane into the nucleus. Anticipated cellular distribution was demonstrated by use of confocal microscopy and cleavage by caspase-3 was shown to be required for the translocation of the GFP signal seen in apoptotic cells. Quantification of apoptosis using the construct revealed similar levels to that obtained with a commercially available apoptosis imaging agent (22.6% versus 20.3%). Moreover, we demonstrated its capacity for use in a high-throughput setting making it a powerful tool for drug development pipelines.

Comparação de mapeamentos do uso da terra por técnicas de geoprocessamento no município de São Lourenço do Sul/RS

A erosão é um processo que ocorre naturalmente no planeta, resultado da modificação constante do relevo. Esse processo, entretanto, tem sido acelerado por conta de usos inadequados das capacidades de cada solo; bem como a retirada de sua cobertura vegetal protetora. A consequência dessa aceleração, geralmente, é percebida na intensificação de desastres naturais, como inundações e deslizamentos. Atualmente o estudo para controle de erosão é caro e demanda tempo. Logo, as técnicas de geoprocessamento vêm como forma de agilizar as análises, poupando tempo e barateando o processo (sem perder a qualidade). O objetivo do trabalho foi analisar dois mapeamentos distintos de uso da terra, e comparar as possíveis incompatibilidades entre eles, indicando provável impacto ambiental decorrente de uso. Através da comparação, fica evidente que alguns solos que são suscetíveis a erosão e possuem baixa disponibilidade hídrica, como as colinas, estão sendo utilizados para cultivo. Em contrapartida, em menor escala, nota-se que os solos de planícies baixas lagunares não estão sendo utilizado para cultivo, conforme estipulado na capacidade original de uso. Apesar do município de São Lourenço do Sul possuir uma classificação para o seu uso do solo, constatou-se que essa capacidade não caracteriza completamente o cenário real, não havendo cumprimento por parte dos moradores nem fiscalização do poder público quanto a esse uso. É necessário, para que se atinja uma redução do alto grau erosivo no município, a criação de planos e programas que facilitem a identificação da área ideal a ser cultivada, bem como as corretas técnicas de plantio e manejo a serem utilizadas por parte do agricultor. Assim, as perdas de solo serão mitigadas e a conservação da área será restaurada.

Confined phosphorus in carbon nanotube-backboned mesoporous carbon as superior anode material for sodium/potassium-ion batteries

Sodium and potassium ion batteries (SIBs and PIBs) hold promise as potential low-cost and large-scale energy storage devices due to the earth abundance of sodium and potassium. Among all proposed anode materials, red phosphorus (P) has been recognized as a promising candidate owing to its high theoretical capacities for use in both SIBs and PIBs (2596 mA h g−1 for Na3P and 843 mA h g−1 for KP); however, its intrinsic insulating property and large volume change during cycling lead to poor cycling and rate performance. To overcome these issues, we have designed and synthesized a carbon nanotube-backboned mesoporous carbon (TBMC) material for the impregnation of red P. The TBMC was synthesized by a synchronic growth of resorcinol-formaldehyde resin/SiO2 on carbon nanotubes, followed by carbonation of the resin and removal of the SiO2. The resulting TBMC was then infiltered with red P at elevated temperatures, forming a P@TBMC composite. In this unique composite, multi-walled carbon nanotubes facilitate the electron transfer due to the high content of sp2 carbon, while the mesoporous carbon layers offer voids to load appropriate amounts of P but leave enough space to alleviate the huge volume change of the P upon sodiation/potassiation. Therefore, the P@TBMC composite exhibits excellent cycling performance and rate capability as the anode for both SIBs and PIBs. For example, the P@TBMC composite shows a high reversible desodiation capacity (~ 1000 mA h g−1 at 0.05 A g−1), superior rate performance (~ 430 mA h g−1 retained at 8 A g−1), and excellent cycle life (no capacity decay for 800 cycles at 2.5 A g−1). More impressively, the P@TBMC, as an anode of PIBs, exhibits electrochemical performance superior to all the reported anodes for PIBs, namely, delivering a reversible capacity of ~ 500 mA h g−1 0.05 A g−1 and a stable capacity of 244 mA h g−1 at 0.5 A g−1 for 200 cycles. The design based on confining active materials into hybrid carbon nanostructures integrated with highly conductive sp2 carbon and porous carbon is expected to shed light on the development of high-performance electrode materials for metal-ion batteries and other energy storage systems.

Performance evaluation of semi-flexible permeable pavements under cyclic loads

ABSTRACTTraditional permeable pavements are constructed with rigid aggregates and have low load-bearing capacity. The crack development due to loads and unpredicted ground movements reduces their service life. The widespread cracks on the surface of conventional asphalt accelerate the pavement structure deterioration and reduce the overall service life. In this research, the end-of-life tyre products shredded to tyre-derived aggregates (TDAs) were utilised along with crushed rock (CR) in different fractions of a porous structure to enhance the flexibility of permeable pavement whilst maintaining the minimum load-bearing capacity for use in footpath and low-volume roads. The transitional behaviour from a semi-rigid structure owing to the rigidity of CR aggregates to a more flexible structure for mixtures at higher TDA content was investigated. The impact of rigid-rigid and flexible-rigid inter-particular contacts at low and high stress levels is investigated. The plastic and recoverable deformations of the flexible-rigid blends under monotonic and repeated loadings are compared. Also, the impact of polyurethane binder content on improving the mixtures flexural strength is investigated. The lightly bonded flexible-rigid mixtures are a viable replacements for traditional porous pavements to improve the load-bearing mechanism and increase the flexibility of pavement.

Absorption, combination and desorption: knowledge-oriented boundary spanning capacities

PurposeThe purpose of this paper is to theoretically develop and empirically explore knowledge absorption, combination and desorption within and between organizations.Design/methodology/approachOn the basis of knowledge-based view and absorptive capacity, the authors have conducted a multiple-case study to develop a theoretically grounded and empirically supported model of intra- and inter-firm knowledge cycles.FindingsFirms identify their knowledge gaps and stocks, both tacit and explicit, undertaking efforts to fill the latter and maximize the value of the former. The paper finds that knowledge exploration, integration and exploitation both within the firm and between firms relies on absorptive, combinative and desorptive capacities. Further, as such capacities are organizationally expensive to maintain, firms will often emphasize one capacity over the other and focus either internally or externally to meet organizational goals.Originality/valueWhile there is extensive research into absorptive capacity and some into combinative capacity, there is little empirical investigation of desorptive capacity and none into the integration of the three concepts; this paper seeks to fill that gap. Moreover, the resulting novel integrative model allows managers and researchers to identify the various capacities in use and their applications within the firm and between firms.

Characterization of the commercial growth curves of Spanish Merino, Fleischschaf, and crossbred lambs in an associative economy context

We examined commercial growth curves of three sheep genotypes in a Second-Grade cooperative context, with Spanish Merino used as a maternal base, Fleischschaf as a paternal base, and crossbred (Fleischschaf × Merino) lambs as the commercial product. We included weight-age data collected from 2013 to 2016 for 9846 lambs of both sexes belonging to 14 herds across the three genotypes. Five of the most-cited models (Brody, von Bertalanffy, Verhulst, Logistic, and Gompertz) were applied to the data, using the determinative coefficient, mean square error, number of iterations, Akaike information coefficient, and the biological coherence of the estimated parameters as best-fitting criteria. The dataset included lamb weights at different ages and sexes, grouped across nine age levels, for a total of 23,299 wt records. Models were fitted according to non-linear regression. The von Bertalanffy model was found to best fit lambs of both sexes for the Spanish Merino breed, whereas the Verhulst model best fit Fleischschaf and crossbred lambs. Parameters of the best-fit curve and derived parameters (inflection age and weight, asymptotic value, growth rate, maturity degree) were estimated for all sex-genetic groups to examine capacities for use as complementary selection criteria in the breeding program, resulting in promising traits for this purpose. Our findings demonstrate that current crossbreeding strategies implemented at the OVISO cooperative, which seek complementarities and/or heterosis, are not achieving the expected results; therefore, we recommend a new strategy for the breeding program. We also found that artificially conceived Spanish Merino lambs exhibited better performance than those conceived naturally, likely due to superior genetics of carefully selected sires.