Low Transmission Rate Research Articles

Fabrication of Bragg stack films of clay nanosheets and polycations via co-polymerization of intercalated monomers and functional interlayer cations.

The fabrication of one-dimensional (1D) crystalline, monodomain nanocomposite films (hybrid Bragg stacks) is still limited to a few combinations of polymers and clay. The main reason is the segregation of clay and polymers driven by the entropic loss faced by the polymer confined in a narrow slit between the nanosheets. By exchanging synthetic sodium-fluorohectorite with vinylbenzyltrimethylammonium chloride, we succeeded in delaminating clay via 1D dissolution in N-methylformamide to obtain a liquid crystalline suspension. By combining this with bisphenol A glycerolate diacrylate, 1D crystalline nanocomposites could be obtained via photopolymerization of doctor bladed wet coatings. Infrared spectroscopy confirmed the co-polymerization of monomers and the organic modifier between the hectorite platelets. This single-phase hybrid material shows very low oxygen and water vapor transmission rates. The incorporation of the modified clay into the polymer leads to an oxygen transmission rate of 0.21 cm3 m-2 day-1 atm-1 at 50% r.h. and 23 °C and a water vapor transmission rate of 0.05 g m-2 day-1 for a coating of 3.7 μm, making this material appropriate for challenging packaging applications.

A Sustainable and Environmentally Friendly Alternative to Plastics: Bioplastics

Traditional plastics made from petrochemicals continue to be extensively employed in packaging because of their strong barrier qualities, rigidity, and tensile and tear strengths. Despite their popularity, plastics have a number of disadvantages, such as a relatively low water vapour transmission rate and a lack of biodegradability. In recent years, we have seen the correct disposal of plastic become a persistent and possibly global environmental issue. Millions of animals have died as a result of improper plastic disposal and land and marine garbage disposal, which reduced soil fertility. Newer concepts for using bioplastics were implemented while keeping in mind the environmental damage and contamination. Bioplastics are a rapidly growing segment of the plastics industry, and they have the potential to play a significant role in addressing some of the environmental challenges posed by traditional petroleum-based plastics. This review aims to provide an overview of the current state of the bioplastics industry, including its brief history, the types of bioplastics that are available, their properties, production processes, and end-of-life considerations. Additionally, the review will explore the advantages and disadvantages of bioplastics compared to traditional plastics, and will consider the future prospects of this rapidly evolving industry.

Analysis of substrate materials in microstrip antenna for biomedical applications

In recent years, Endoscopic assessment of disease activity is an essential clinical practice which plays a significant role in medical diagnosis, prognosis, monitoring etc. These techniques mostly utilize non-invasive methods to diagnose endoscopic diseases like gastrointestinal tract diseases, tumors, infections etc. But these applications are critically limited by a range of factors like size of capsule, low data transmission rates and low antenna propagation efficiency. So, the design of an antenna with superior performance parameters is explored in this paper. The antenna is designed to be used for ISM band and preferred for UWB applications. The antenna chosen is a microstrip antenna which is designed to operate at a resonant frequency of 2.4 GHz. The substrate material chosen is FR-4 having a dielectric constant of 4.3. The designed antenna exhibits additional advantages like good isolation, low profile, easy of fabrication and good isolation. The designed antenna provides a return loss less than −10 dB.Final antenna structure is composed of substrate FR4 Epoxy with Defective Ground Structure commonly known as DGS. The antenna performance using different substrates materials namely Duroid, Rogers 5880 and Teflon was also compared in terms of Return loss, Gain and VSWR in this paper. The different antenna parameters such as Return loss, VSWR, Directivity, Radiation pattern, Gain, Bandwidth were measured to finalize the antenna design. All the exhibited simulation results are implemented using HFSS software.

Research on User Pairing Techniques Based on NOMA in Cognitive Radio Networks

This paper outlined a Non-Orthogonal Multiple Access (NOMA) grouping transmission scheme for cognitive radio networks. To address the problems of small channel gain difference of the middle part users caused by the traditional far-near pairing algorithm, and the low transmission rate of the traditional Orthogonal Multiple Access (OMA) transmission, a joint pairing algorithm was proposed, which provided multiple pairing schemes according to the actual scene. Firstly, the secondary users were sorted according to their channel gain, and then different secondary user groups were divided, and the far-near pairing combined with (Uniform Channel Gain Difference (UCGD) algorithm was used to group the secondary users. After completing the user pairing, the power allocation problem was solved. Finally, the simulation data results showed that the proposed algorithm can effectively improve the system transmission rate.

A type of energy saving strategy with adaptive link transmission rates and a sleep mode for edge computing networks

As the communication industry develops, issues such as how to conserve energy, reduce environmental pollution, and realize more sustainable communication are becoming more pressing. In this paper, a type of energy saving strategy for edge computing networks is proposed. In this energy saving strategy, links will transfer to the sleep mode from the active mode as soon as there are no packets ready for transmission, i.e., the link will be idle once the output buffer is empty. In the active mode, the link transmission rate is adaptively adjusted based on the number of packets in the output buffer with two thresholds. In order to capture the digital nature of modern communication and numerically evaluate the system performance, we establish a discrete-time multiple-vacation queue with variable service rates to model the proposed energy saving strategy. By using the method of a matrix-geometric solution, we analyze the queueing model in the steady state, and obtain the formulas for the performance measures in terms of the energy saving rate of the system, the average latency of packets and the utilization of the edge server. Moreover, we provide numerical results with analysis and simulation to investigate the influence of the system parameters on the system performance. Finally, we construct a cost function and develop an intelligent searching algorithm to give the jointly optimal values for the two buffer thresholds and the lower transmission rate of packets.

Multi-Task Partial Offloading with Relay and Adaptive Bandwidth Allocation for the MEC-Assisted IoT

The fifth-generation (5G) wireless network is visualized to offer many types of services with low latency requirements in Internet of Things (IoT) networks. However, the computational capabilities of IoT nodes are not enough to process complex tasks in real time. To solve this problem, multi-access edge computing (MEC) has emerged as an effective solution that will allow IoT nodes to completely or partially offload their computational tasks to MEC servers. However, the large communication delay at a low transmission rate for nodes far from the access point (AP) makes this offloading less meaningful. This paper studies joint multi-task partial offloading from multiple IoT nodes to a common MEC server collocated with an AP, and it uses relay selection to help nodes far from the AP. The computation time of all tasks is minimized by adaptive task division and resource allocation (bandwidth and computation resource), and it is solved with an evolutionary algorithm. The simulation results confirm that the proposed method with both relay selection and adaptive bandwidth allocation outperforms the methods with neither or only one function.

Design of a Hybrid Refractive/Diffractive Lens System for Broadband UV.

Traditional broadband UV optical designs often have complex structural problems and cannot meet the current requirements of light and miniaturization. In this study, we first design the substrate material of double-layer diffractive optical elements (DOEs) in the 0.23-0.8 μm band, optimize the diffraction efficiency and analyze the effect of the angle of incidence on the diffraction efficiency of double-layer DOEs. Second, we design a refractive lens system and a refractive/diffractive hybrid lens system with double-layer DOEs designed for a wide UV wavelength range of 0.23-0.8 μm, a half field of view of 15 mm, an objective aperture of 0.1 and a magnification of 1. The refractive/diffractive hybrid lens system designed with seven lenses produces a higher image quality than the refractive lens system. The novel design is an effective solution to the problem of the low transmission rate of traditional UV refractive lens systems.

Looking beyond facilities to eliminate vertical transmission

In The Lancet HIV, Goodluck Willey Lyatuu and colleagues1 present large-scale estimates of vertical HIV transmission in Dar es Salaam, Tanzania. The authors prospectively follow a cohort of women who presented for antenatal care from 2015 to 2017 and estimate vertical transmission rates in their infants up to 18-months post-partum. Of 13 251 women followed over this period, 159 infants were diagnosed with HIV, representing an impressively low vertical transmission rate of 1·4%. Factors related to poor care-seeking and adherence behaviours were most strongly associated with vertical transmission: late presentation to antenatal care, lack of previous ART use, advanced HIV disease, and use of second-line ART regimens.

Low secondary attack rate after prolonged exposure to sputum smear positive miliary tuberculosis in a neonatal unit

BackgroundSeveral neonatal intensive care units (NICU) have reported exposure to sputum smear positive tuberculosis (TB). NICE guidelines give support regarding investigation and treatment intervention, but not for contact definitions. Data regarding the reliability of any interferon gamma release assay (IGRA) in infants as a screening test for TB infection is scarce. We report an investigation and management strategy and evaluated the viability of IGRA (T-Spot) in infants and its concordance to the tuberculin skin test (TST).MethodsWe performed an outbreak investigation of incident TB infection in a NICU after prolonged exposure to sputum smear positive miliary TB by an infant’s mother. We defined individual contact definitions and interventions and assessed secondary attack rates. In addition, we evaluated the technical performance of T-Spot in infants and compared the results with the TST at baseline investigation.ResultsOverall, 72 of 90 (80%) exposed infants were investigated at baseline, in 51 (56.7%) of 54 (60%) infants, follow-up TST at the age of 6 months was performed. No infant in our cohort showed a positive TST or T-Spot at baseline. All blood samples from infants except one responded to phytohemagglutinin (PHA), which was used as a positive control of the T-Spot, demonstrating that cells are viable and react upon stimulation. 149 of 160 (93.1%) exposed health care workers (HCW) were investigated. 1 HCW was tested positive, having no other reason than this exposure for latent TB infection. 5 of 92 (5.5%) exposed primary contacts were tested positive, all coming from countries with high TB incidences. In total, 1 of 342 exposed contacts was newly diagnosed with latent TB infection. The secondary attack rate in this study including pediatric and adult contacts was 0.29%.ConclusionThis investigation highlighted the low transmission rate of sputum smear positive miliary TB in a particularly highly susceptible population as infants. Our expert definitions and interventions proved to be helpful in terms of the feasibility of a thorough outbreak investigation. Furthermore, we demonstrated concordance of T-Spot and TST. Based on our findings, we assume that T-Spot could be considered a reliable investigation tool to rule out TB infection in infants.

Parallel Combined Spread Spectrum Error Analysis And Succesive Error Correction Method

Traditional spread spectrum techniques provide a strong anti-interference capability but a relatively low transmission rate. This is addressed by the parallel combination spread spectrum technique which provides higher transmission efficiency, security, and spread gain. Nevertheless, the receiver of a parallel combined spread spectrum system requires to distinguish multiple spread spectrum sequences. Therefore, any reception errors are propagated in the receiver hence leading to a larger number of errors. Moreover, spread spectrum sequences with different mode values experience different probability of errors at the receiver. The existing analysis of the error location in the parallel combined spread spectrum is only an estimate after countless experiments. In this paper, we theoretically analyze the probability of correct discrimination of parallel combination spread spectrum with different modulus values. Furthermore, according to the probability analysis of correct discrimination therefore the parallel combination spread spectrum is improved. This significantly reduces the bit error rate of the system and improves the reliability only with a slight degradation of transmission efficiency.

Guest Editorial: Emerging Trends and Challenges in Internet-of-Underwater-Things

Internet-of-Underwater-Things (IoUT) is a network of smart interconnected underwater objects. Recently, IoUT has shown its applicability in numerous scenarios such as marine life monitoring, off-shore exploration, underwater lost-treasure discovery, sports, assisted navigation, location awareness, environmental monitoring (e.g., monitoring of water quality, water pollution, water pressure or water temperature), water-based disasters (e.g., tsunami or nuclear accident), defense systems (e.g., surveillance systems or submarine detection) and several other applications. Even though IoUT systems are key enabler in underwater communication, they face challenges due to unreliable transmission medium, unstable radio signals, limited range, low bandwidth, inborn noise, low transmission rate, slow propagation speed, node mobility, lower resources and limited battery capacity. These challenges cause issues in channel modeling, optimal routing, security, privacy, communication overhead, congestion control, packet error rate, packet latency, energy consumption etc. In this respect, this Special Issue (SI) aims to address some of the aforementioned challenges.

Adaptive Sentinel Testing in Workplace for COVID-19 Pandemic.

Testing and isolation of infectious employees is one of the critical strategies to make the workplace safe during the pandemic for many organizations. Adaptive testing frequency reduces cost while keeping the pandemic under control at the workplace. However, most models aimed at estimating test frequencies were structured for municipalities or large organizations such as university campuses of highly mobile individuals. By contrast, the workplace exhibits distinct characteristics: employee positivity rate may be different from the local community because of rigorous protective measures at workplace, or self-selection of co-workers with common behavioral tendencies for adherence to pandemic mitigation guidelines. Moreover, dual exposure to COVID-19 occurs at work and home that complicates transmission modeling, as does transmission tracing at the workplace. Hence, we developed bi-modal SEIR (Susceptible, Exposed, Infectious, and Removed) model and R-shiny tool that accounts for these differentiating factors to adaptively estimate the testing frequency for workplace. Our tool uses easily measurable parameters: community incidence rate, risks of acquiring infection from community and workplace, workforce size, and sensitivity of testing. Our model is best suited for moderate-sized organizations with low internal transmission rates, no-outward facing employees whose position demands frequent in-person interactions with the public, and low to medium population positivity rates. Simulations revealed that employee behavior in adherence to protective measures at work and in their community, and the onsite workforce size have large effects on testing frequency. Reducing workplace transmission rate through workplace mitigation protocols and higher sensitivity of the test deployed, although to a lesser extent. Furthermore, our simulations showed that sentinel testing leads to only marginal increase in the number of infections even for high community incidence rates, suggesting that this may be a cost-effective approach in future pandemics. We used our model to accurately guide testing regimen for three campuses of the Jackson Laboratory.

Effectiveness of SARS-CoV-2-inactivated vaccine and the correlation to neutralizing antibodies: A test-negative case-control study.

Severe acute respiratory syndrome coronavirus 2breakthrough infection in highly vaccinated populations raises study on the effectiveness for inactivated vaccine, including effectiveness of the vaccine dose, the continuance of effectiveness, the effectiveness against severe/critical coronavirus disease 2019and against secondary attacks. A population of 10 870 close contacts were investigated in a Delta variant's epidemic. The effectiveness of vaccination was estimated in a test-negative case-control study. In addition, serum was used to detect neutralizing antibodies, to explore their correlation to effectiveness. The vaccine effectiveness (VE) values were estimated for populations aged 12 years or older. The overall adjusted VE was 56.2%and a two-dose vaccine was more effective than a one-dose vaccine (56.7% vs. 43.8%). In addition, the population that got the second dose vaccine within 2 months showed higher VE than the population vaccinated for longer than 2 months (61.5% vs. 52.3%). Among the population who vaccinated 2 doses or within 2 months, a higher level of neutralizing antibodies was observed. For infected cases, vaccinated populations showed lower rates of transmission (2.63% vs. 4.36%). Further, those vaccinated cases, who were not found causing transmission, had a higher level of antibodies. The study provided a full view of the effectiveness of inactivated vaccines in a real-world setting. The time-related VE against infection and lower transmission of breakthrough vaccinated cases were observed, which may indicate that a necessity of a booster vaccine to maintain the effectiveness and high level of neutralizing antibody.

Transmission of Xylella fastidiosa subsp. pauca ST53 by the Sharpshooter Cicadella viridis From Different Source Plants and Artificial Diets.

The sharpshooter Cicadella viridis L. (Hemiptera: Cicadellidae) is the most common sharpshooter in Europe and, given its xylem feeding behavior, is considered a potential vector of the plant pathogenic bacterium Xylella fastidiosa Wells et al. (Xanthomonadales: Xanthomonadaceae). We tested X. fastidiosa subsp. pauca ST53 (Xfp) transmission capabilities of C. viridis adults, namely 1) acquisition efficiency from four host plant species-periwinkle, milkwort, lavender, alfalfa-and from two artificial diets (PD3 and Xfm), 2) inoculation efficiency to periwinkle at different times post acquisition from different plant and artificial diet sources. The main European vector species-Philaenus spumarius L. (Hemiptera: Aphrophoridae)-was used as a control. C. viridis was able to acquire Xfp from periwinkle, milkwort, and lavender, although with low efficiency (3-16%) and from artificial diets (23-25%). Successful inoculation on periwinkle was extremely rare, being observed only three times, following feeding on milkwort plant and PD3 artificial diet sources. Our study shows that C. viridis is not a relevant vector of Xfp, given the very low transmission rate in controlled conditions, and the inability to feed on olive. The low efficiency reported here correlates with ecological constraints of the vector (mainly monocots host plants, humid environments) that make it difficult to forecast a relevant role in dispersing X. fastidiosa, at least within the present distribution of the exotic bacterium in Europe. However, a possible role of this species in spreading Xf in other agroecosystems, e.g., vineyard and stone fruits grown in humid areas, cannot be excluded.

Design of Placement Delivery Arrays for Coded Caching With Small Subpacketizations and Flexible Memory Sizes

Coded caching is an emerging technique to reduce the data transmission load during the peak-traffic times. In such a scheme, each file in the data center or library is divided into a number of packets to pursue a low broadcasting rate based on the designed placements at each user’s cache. However, the implementation complexity of this scheme increases with the number of packets. It is crucial to design a scheme with a small subpacketization level, while maintaining a relatively low transmission rate. Recently, a combinatorial structure called placement delivery array (PDA) was proposed as an effective tool to design coded caching schemes with a relatively low subpacketization level. This paper proposes a novel PDA construction by selecting proper orthogonal arrays (POAs), which generalizes the existing construction but with a more flexible memory size. Based on the proposed PDA construction, an effective transform is further proposed to enable a coded caching scheme to achieve a smaller subpacketization level. Moreover, two new coded caching schemes with the coded placement are derived. It is shown that the proposed schemes can yield a lower subpacketization level or transmission rate over the benchmark schemes.

Fingerprinting of Mycobacterium tuberculosis isolates by MIRU-VNTR genotyping and detection of isoniazid resistance by real-time PCR.

Introduction. Tuberculosis (TB) is a great public health problem in developing countries such as Egypt. Genotyping of Mycobacterium tuberculosis isolates has a prominent role in the field of TB prevention.Aim. This study aimed to evaluate real-time PCR using Minor Groove Binder (MGB) probes and to identify circulating lineages/sub-lineages of M. tuberculosis and their transmission patterns.Hypothesis. We hypothesize that MIRU-VNTR technique is efficient in identifying circulating M. tuberculosis lineages in Egypt.Methodology. Fifty sputum specimens positive for acid-fast bacilli were included. Isoniazid (INH) resistance was detected using the 1 % proportion method. Real-time PCR using MGB-probes was used for simultaneous detection of TB infection and INH resistance. Partial sequencing of the katG gene was used to confirm INH resistance results. A standard 15 Mycobacterial Interspersed Repetitive Unit Variable Number Tandem Repeat (15-MIRU-VNTR) approach was used for genotyping through the MIRU-VNTRplus online platform.Results. Only seven specimens showed phenotypic resistance to INH. M. tuberculosis was detected in all samples, while a mutation in the katG gene codon 315 was detected only in five samples, which were also phenotypically INH-resistant. Sequencing of the katG gene showed codon 315 mutation genotypically and phenotypically in the five INH-resistant isolates. Molecular genotyping of M. tuberculosis isolates revealed that the majority of isolates (26/50, 52 %) belonged to the S family of lineage_4. A low clustering rate (2 %) was observed among our isolates. According to the Hunter-Gaston Discriminatory Index (HGDI), 11 MIRU-VNTR loci were highly or moderately discriminative, while four loci were less polymorphic.Conclusion. MIRU-VNTR genotyping revealed a low clustering rate with a low recent transmission rate of M. tuberculosis strains in Alexandria, Egypt.

Water and oil-resistant paper materials based on sodium alginate/hydroxypropyl methylcellulose/polyvinyl butyral/nano-silica with biodegradable and high barrier properties

Despite many technical challenges in the development of safe and environmentally friendly food packaging paper materials with excellent water and oil resistance using simple methods, producing paper-based functional materials using bio-based polymers is currently an important topic in the food packaging industry. In this study, novel water and oil-resistant coatings for the paper were developed through the combination of sodium alginate (SA), hydroxypropyl methylcellulose (HPMC), polyvinyl butyral (PVB), and hydrophobic silica nanoparticles (HSNPs). To impart oil-repellency to paper, SA and HPMC were first mixed uniformly and coated on the base paper, which was pre-treated with calcium chloride solution. A compact and tough coating layer was formed on paper due to the hydrogen bonding between SA and HPMC molecules, and the crosslinking between SA and Ca2+ ions in the base paper. High water resistance of the paper was achieved through the coating of PVB and HSNPs on top of the coating of SA/HPMC. The final coated paper demonstrated outstanding oil resistance (kit rating: 12/12), water resistance (Cobb value: 4.23 g/m2), low water vapor transmission rate (100 g/m2·24 h), and improved mechanical properties. This fluorine-free, and biodegradable barrier paper will find excellent applications in the food packaging industry.

Morphea overlapping borderline leprosy: An unusual association

Leprosy, or Hansen’s disease, is a chronic infectious disease with a low transmission rate, affecting the skin, peripheral nerves, eyes, and mucous membranes of the upper respiratory tract, yet it may also be systemic. Cases of borderline leprosy are the acute or subacute stages of the disease. They are immunologically unstable and reflect the gradual variation in resistance against the etiological agent. Localized scleroderma or morphea is a fibrosing disease of the skin and underlying tissues that results from the disrupted function of growth factors (platelet-derived growth factor, i.e., PDGF) and receptor expression (as in the case of transforming growth factor b, i.e., TGF-b). Herein, we report a female patient with borderline tuberculoid leprosy (BT) who, during multidrug treatment (MDT), developed an indurated lesion of morphea exactly on the surface of an infiltrated patch.

A novel hybrid seed production technology based on a unilateral cross-incompatibility gene in maize.

Hybrid seed production technology (SPT) using genic recessive male sterility is of great importance in maize breeding. Here, we report a novel SPT based on a maize unilateral cross-incompatibility gene ZmGa1F with an extremely low transgene transmission rate (TTR). Proper pollen-specific ZmGa1F expression severely inhibits pollen tube growth leading to no fertilization. The maintainer line harbors a transgene cassette in an ipe1 male sterile background containing IPE1 to restore ipe1 male fertility, ZmGa1F to prevent transgenic pollen escape, the red fluorescence protein encoding gene DsRed2 for the separation of male sterile and fertile seeds, and the herbicide-resistant gene Bar for transgenic plant selection. When the maintainer line is selfed, gametes of ipe1/transgene and ipe1/- genotypes are produced, and pollen of the ipe1/transgene genotype is not able to fertilize female gametes due to pollen tube growth inhibition by ZmGa1F. Subsequently, seeds of ipe1/ipe1 and ipe1/transgene genotypes are produced at a 1:1 ratio and could be separated easily by fluorescence-based seed sorting. Not a single seed emitting fluorescence is detected in more than 200,000 seeds examined demonstrating that the pollen-tube-inhibition (PTI)-based TTR is lower than what has been reported for similar technologies to date. This PTI-based SPT shows promising potential for future maize hybrid seed production.

PSXIII-7 Field Testing of Lora-wan Sensors for Real-Time Tracking and Biosensing of Brangus and Raramuri Criollo Cattle Grazing a Small Pasture

Abstract The study’s objective was to investigate the use of Internet of Things (IoT) biosensors using Long Range Wide Area Network (LoRa-WAN) communication to compare the foraging behavior of two desert adapted cattle breeds. Two groups of mature Brangus (BA) and Raramuri Criollo (RC) cows were introduced into a small irrigated pasture (38ha) at the New Mexico State University’s Clayton Livestock Research Center during Dec-Jan, 2021 (41-days). The real-time position and activity count data (15- and 1-minute interval, respectively) were retrieved continuously from 4 BA and 5 RC cows collared with commercially available trackers (Abeeway Industrial-trackers). Response variables derived from GPS records included daily distance traveled (Dist) and daily area explored (Area). Response variables derived from accelerometers included daily percentage motion (%Act) and cumulative activity data (CumAct). All variables were grouped into six consecutive weekly periods and analyzed by a repeated measures mixed model that included the fixed effects of BREED, WEEK, and the BREED*WEEK interaction in a completely randomized design. A significant (P< 0.01) BREED*WEEK interaction was detected on all GPS-derived variables, with RC exhibiting a trend to explore larger areas than BA (P=0.06). For the accelerometer-derived variables, the BREED*WEEK interaction was only significant (P=0.01) for CumAct. Overall, BA spent a larger percentage of the day active (%Act; BA= 76.74 vs. RC= 73.16; P=0.02), while investing a significantly greater overall activity (CumAct; BA= 8816.63 vs. RC= 6311.31; P=0.03) compared to RC cows. The insensitivity of GPS-derived variables is hypothesized to be the result of aggregating errors associated with less frequent GPS location measurements coupled with position errors (~5m) and a low success rate of data packet transmission (~40%). The spatial scale of the study is hypothesized to have influenced the foraging behavior differences that were observed between the breeds, and the better performance of the accelerometer vs. GPS-derived variables.