Efficacy of a remote-controlled, positive-reinforcement, dog-training system for modifying problem behaviors exhibited when people arrive at the door

This study was conducted to determine the efficacy of a multi-step, positive-reinforcement training protocol, involving a remote-controlled food reward dispenser, for treatment of excessive barking, jumping, and crowding of the door by dogs when people come to the door. In Experiment 1, we tested the multi-step protocol in a laboratory setting to determine whether the protocol is successful in a controlled environment when implemented by dog trainers. Six dogs with a history of problem behaviors at the door were trained to run to a platform with a rug on it, lie down and stay (“down-stay”) for 1 min while common household door distractions such as loud knocking, ringing doorbells, and running people were presented. The dog's ability to remain in a down-stay for 1 min with such distractions was measured before and after training. During training, the number of training trials required and the numbers of trials performed correctly and incorrectly were recorded for each dog. The results revealed that dogs remained in a down-stay with distractions significantly longer after training (60 ± 0.0 s) than before (5 ± 1.18 s) (P = 0.016). Dogs completed the training protocol in 8 d with only 8.4% incorrect trials, and in a similar number of trials with a coefficient of variation of 10.6%. These results indicated that this protocol was a good candidate for testing in a clinical setting, a home situation with owners doing the training. In Experiment 2, 15 dogs were trained by their owners to run to a rug or bed, lie down, and stay for 1 min while their owners answered the door. After training, barking decreased from 19.3 ± 4.62 barks/min to 2.1 ± 0.79 barks/min (P < 0.0001), jumping decreased from 8.2 ± 2.12 jumps/min to 0.02 ± 0.02 jumps/min (P < 0.0005) and time spent within 0.3 m of the door when visitors were outside decreased from 84.5% ± 4.23% to 0.0% ± 0.00% (P < 0.0001). Percent time spent in contact with the visitor when the visitor was inside decreased from 69.2% ± 4.19% to 0.18% ± 0.13% (P < 0.0001). Additionally, owner perception of their dog's behavior improved significantly (P < 0.0001). Six dogs that were not trained with the protocol showed no significant improvement (P = 0.344).     

Clonal Dynamics of Nasal Staphylococcus aureus and Staphylococcus pseudintermedius in Dog-Owning Household Members. Detection of MSSA ST398

The objective of this study was to investigate the dynamics of nasal carriage by Staphylococcus aureus (SA) and Staphylococcus pseudintermedius (SP) among healthy dog-owning household members involved in 7 previous index cases of suspected anthropozoonotic (n = 4) and zoonotic (n = 3) interspecies transmission [4 direct cases, identical SA (n = 3) or SP (n = 1) in owner and dog; three indirect, SP in owner (n = 2) or SA in dog (n = 1)]. Co-carriage with methicillin-resistant coagulase-negative staphylococci (MRCoNS) was also evaluated. Sixteen owners and 10 dogs were sampled once every three months for one year. In total, 50 SA and 31 SP were analysed by MLST, and SA also by spa typing. All isolates were subjected to ApaI/SmaI-PFGE and antimicrobial resistance and virulence profiles were determined. All index owners were persistent SA carriers in all direct-anthropozoonotic transmission cases, while only one dog was persistent SA carrier. Owner and dog exhibited a persistent SP carriage status in the direct-zoonotic transmission case. SP was maintained in the index human over time in one indirect-zoonotic transmission case. Only one SP was methicillin-resistant. SA belonged to genetic backgrounds of MRSA pandemic clones: CC45, CC121, CC30, CC5 and CC398. Three individuals carried a MSSA t1451-ST398 clone with the erm(T)-cadD/cadX resistance genes. SA or SP were persistently detected in the nasal cavity of 7 (43.8%) and 2 (12.5%) owners, and in one and 2 dogs, respectively. SA was recovered as the single species in 10 owners and in one dog; SP in 3 owners and 4 dogs; and both bacterial species in one owner and 4 dogs. Co-carriage of SA or SP with MRCoNS isolates was common (30.7%). This is the first study on the dynamics of nasal carriage of SA and SP in healthy pet-owning household members. Dog-contact may play a role in the staphylococcal species distribution of in-contact individuals.     

Corpuscular oxidative stress in desert sheep naturally deficient in copper

Oxidative stress arises when there is an imbalance between radical-generating and radical-scavenging activity; it may therefore cause an increase in oxidation products and cell damage. This study aimed to determine antioxidant status, lipid peroxidation, and their relation to anemia of grazing sheep deficient in copper (Cu). For this purpose, 39 male lambs of native (Balady) breed, aged 6–7 months and reared in El-Dakhla oasis (in the western Egyptian desert), were divided according to plasma Cu (pCu) concentration into three groups, marginally deficient (MD, pCu = 4–8 μmol/l, n = 12), functionally deficient (FD, pCu < 3 μmol/l, n = 12) and control (pCu > 9 μmol/l, n = 15). Jugular blood was sampled for determination of red blood cell count (RBC), packed cell volume (PCV), hemoglobin concentration (Hb), plasma ceruloplasmin activity (pCp), antioxidant activities of erythrocytic superoxide dismutase (eSOD), catalase (eCAT), glutathione peroxidase (eGSH-Px), and levels of erythrocytic malondialdehyde (eMDA, as a biomarker of lipid peroxidation). The Cu-deficient lambs were characterized by microcytic hypochronic anemia accompanied by decreased pCp, eSOD, eCAT and eGSH-Px activities and increased eMDA level when compared to the controls. The indices of anemia, pCp and eSOD were lower and eMDA was higher in FD compared to MD lambs. The enhanced eMDA was strongly correlated (P < 0.01) with the inhibited activity of pCu (r = −0.79), pCp (r = −0.65) and eSOD (r = −0.71) and to a lesser extent (P < 0.05) with eGSH-Px (r = −0.38) and eCAT (r = −0.41). In addition, eMDA was negatively correlated (P < 0.01) with RBC (r = −0.75), PCV (r = −0.69) and Hb (r = −0.72). This study suggests that Cu-deficient lambs incur an erythrocytic oxidative damage secondary to impaired oxidant defenses, which may be one of the mechanisms underlying Cu deficiency-induced anemia in grazing sheep.     

Dog and owner demographic characteristics and dog personality trait associations

The aim of this study was to analyze the relationships between four personality traits (calmness, trainability, dog sociability and boldness) of dogs (Canis familiaris) and dog and owner demographics on a large sample size with 14,004 individuals. German speaking dog owners could characterize their dog by filling out a form on the Internet. There were five demographic variables for dogs and nine for owners. Two statistical methods were used for investigating the associations between personality and demographic traits: the more traditional general linear methods and regression trees that are ideal for analyzing non-linear relationships in the structure of the data. The results showed that calmness is influenced primarily by the dog's age, the neutered status, the number of different types of professional training courses (e.g. obedience, agility) the dog had experienced and the age of acquisition. The least calm dogs were less than 2.5 years old, neutered and acquired after the first 12 weeks of age, while the calmest dogs were older than 6.9 years. Trainability was affected primarily by the training experiences, the dog's age, and the purpose of keeping the dog. The least trainable dogs had not received professional training at all and were older than 3 years. The most trainable dogs were those who participated in three or more types of professional training. Sociability toward conspecifics was mainly determined by the age, sex, training experience and time spent together. The least sociable dogs were older than 4.8 years and the owners spent less than 3 h with the dog daily. The most sociable dogs were less than 1.5 years old. Males were less sociable toward their conspecifics than females. Boldness was affected by the sex and age of the dog and the age of acquisition. The least bold were females acquired after the age of 1 year or bred by the owner. The boldest dogs were males, acquired before the age of 12 weeks, and were younger than 2 years old. Other variables, including the owner's gender, age, education, previous experience with dogs, the number of people and dogs in the household, and purpose of keeping the dogs had minor, but detectable effects. The results suggest that on-line questionnaires are a very effective means for collecting data about dog behavior, especially if owners are motivated by instant feedback. However, note that the characteristics of dogs in the present study were reported by the owners, and the associations with the traits do not necessarily represent a causal relationship.     

The Canine Cuteness Effect: Owner-Perceived Cuteness as a Predictor of Human–Dog Relationship Quality

ABSTRACT

The modern domestic dog's primary function is as a human companion. A strong human–dog relationship may be beneficial to both parties but not all relationships are successful. There is currently no consensus on why some dog–owner relationships flourish and others fail, but relationship quality may be partly influenced by canine characteristics. The extent to which canine cuteness and canine personality factors predict human–dog relationship quality was examined. In study 1, 668 dog owners completed two relationship-quality surveys, rated their dog's personality and physical cuteness, and were invited to submit a photograph of their dog. Personality measures and cuteness ratings predicted each measure of relationship quality, with cuteness being the strongest unique predictor in three of seven standard multiple regression models (all p<0.001). In study 2, 873 independent participants were presented with one of 42 images selected from those provided in study 1. Participants rated the dog's cuteness and its likely personality attributes. Strangers (M=6.69, SD=0.83) typically rated each dog as being less cute than did the owner (M=8.93, SD=1.80; t(41₎=7.39, p<0.001, two tailed), and how cute they perceived the dog to be influenced their ratings of some aspects of its likely personality. Measures of relationship quality provided by owners were not significantly associated with stranger cuteness ratings or with the degree of difference between owner and stranger cuteness ratings. These results suggest a bi-directional relationship between perceived cuteness and other attributes: cute dogs are perceived to have more desirable personality traits, but having a strong relationship with a dog may also inflate its perceived cuteness. These findings have implications for those involved in dog breeding, selection, and training, as well as shelter management.     

Surface-enhanced Raman spectroscopy combined with atomic force microscopy for ultrasensitive detection of thrombin

Indole-3-acetic acid (IAA) amide conjugates play an important role in balancing levels of free IAA in plant cells. The GH3 family of proteins conjugates free IAA with various amino acids. For example, auxin levels modulate expression of the Oryza sativa (rice) GH3-8 protein, which acts to prevent IAA accumulation by coupling the hormone to aspartate. To examine the kinetic properties of the enzyme, we developed a liquid chromatography–tandem mass spectrometry (LC–MS/MS) assay system. Bacterially expressed OsGH3-8 was purified to homogeneity and used to establish the assay system. Monitoring of the reaction confirms the reaction product as IAA–Asp and demonstrates that production of the conjugate increases proportionally with both time and enzyme amount. Steady-state kinetic analysis using the LC–MS/MS-based assay yields the following parameters: V/E_t^IAA = 20.3 min⁻¹, K_m^IAA = 123 μM, V/E_t^ATP = 14.1 min⁻¹, K_m^ATP = 50 μM, V/E_t^Asp = 28.8 min⁻¹, K_m^Asp = 1580 μM. This is the first assignment of kinetic values for any IAA–amido synthetase from plants. Compared with previously described LC- and thin-layer chromatography (TLC)-based assays, this LC–MS/MS method provides a robust and sensitive means for performing direct kinetic studies on a range of IAA-conjugating enzymes.     

The efficacy of systematic desensitization for treating the separation-related problem behaviour of domestic dogs

The evaluation of systematic desensitization to treat separation-related problem behaviours, such as destruction of property, excessive barking, or house-soiling, has tended to rely on single case-studies. Eight dogs exhibiting separation-related behaviour, and their owners, participated in a controlled experiment using a within-subjects design to evaluate the efficacy of a combination of systematic desensitization and counter-conditioning. Treatment produced significant reductions in both the frequency (T(9)) = 0.0, P = 0.008) and the severity (T(9)) = 0.0, P = 0.008) of separation-related behaviours compared to baseline. Six dogs, for which follow-up data were obtained three months after treatment ended, showed almost complete elimination of the problem behaviour. The use of counter-conditioning, and other behavioural advice, did not appear to be related to the success of the treatment, suggesting that systematic desensitization was the critical element. Speed of progress and final success was not related to the consistency with which the owners applied systematic desensitization, indicating that even when owners apply systematic desensitization haphazardly, it can still be successful in treating separation-related behaviour in dogs.     

Association of DLA‐DQB1 alleles with exocrine pancreatic insufficiency in Pembroke Welsh Corgis

Exocrine pancreatic insufficiency (EPI) is a digestive disorder resulting from the insufficient secretion of enzymes from the pancreas. In dogs, this condition is often attributed to pancreatic acinar atrophy, wherein the enzyme‐producing acinar cells are believed to be destroyed through an autoimmune process. Although EPI affects many diverse breeds, to date, molecular studies have been limited to the German Shepherd dog. A recent study of major histocompatibility genes in diseased and healthy German Shepherd dogs identified both risk and protective haplotypes. Herein, we genotyped DLA‐DQB1 in Pembroke Welsh Corgis to determine whether dog leukocyte antigen alleles contribute to the pathogenesis of EPI across dog breeds. We evaluated 14 affected and 43 control Pembroke Welsh Corgis, which were selected based on an age of onset similar to German Shepherd dogs. We identified one protective allele (odds ratio = 0.13, P‐value = 0.044) and one risk allele (odds ratio = 3.8, P‐value = 0.047). As in German Shepherd dogs, the risk allele is a duplication of DLA‐DQB1 (alleles DQB1*013:03 and 017:01); however, Pembroke Welsh Corgis have acquired a single polymorphism on DQB1*017:01. Thus, the DLA‐DQB1 duplication is a risk allele for EPI in at least two breeds.     

A note on the effectiveness of behavioural rehabilitation for reducing inter-dog aggression in shelter dogs

The effectiveness of a rehabilitation program for reducing inter-dog aggression was evaluated at the municipal animal shelter. Sixteen dogs (of 60 examined) met the study criteria of medium inter-dog aggression as determined by an inter-dog aggression test. These dogs received a 10-day treatment of daily rehabilitation for 30 min (rehabilitation group, n = 9) or daily release into an outdoor enclosure for 30 min (control group, n = 7). Rehabilitation consisted of desensitising and counter-conditioning dogs to the approach of other “stimulus” dogs. Most dogs in the rehabilitation group showed a decline in aggression scores when re-tested after the last treatment (day 11), and differed significantly from the control dogs which showed either an increase or no change in aggression scores (U = 8.5, P < 0.01). Rehabilitation dogs also showed lower frequencies of aggressive body postures (“facing the stimulus dog”, P < 0.05, and “stiff posture”, P < 0.10) and higher frequencies of less assertive postures (“ears back”, P < 0.05, and “lowered neck”, P < 0.10) on day 11. The differences between groups were no longer significant when a reduced sample of dogs was tested 1 week after rehabilitation ended (day 18). The study shows short-term reduction of inter-dog aggression through rehabilitation, but further work is needed on effective ways of maintaining the behavioural change.     

Functional IL-18 promoter gene polymorphisms in Tunisian nasopharyngeal carcinoma patients

Objectives: There is growing evidence suggesting that IL-18 levels may affect individual to virus-associated neoplasia and that single nucleotide polymorphisms (SNPs) within the gene may influence its production. In this study we wanted to know whether IL-18 polymorphisms at positions −607 C/A and −137 G/A are associated with susceptibility and/or are markers of nasopharyngeal carcinoma (NPC) prognosis. Methods: Using the restriction fragment length polymerase chain reaction (RFLP-PCR), 163 Tunisian patients and 164 healthy controls were genotyped. Results: No significant association was found between each studied polymorphism and NPC. However, we noted that the −607 A allele, which is associated with lower IL-18 production, increased the risk of advanced tumor stages (OR = 3.59; P = 0.017) and that this risk was more pronounced among the older patient’s age at onset (OR = 3.85; P = 0.012). Moreover, the significant difference in CA/GG haplotype frequency distribution between young and older patients supported the idea that NPC disease has biologically different features between age sub-groups. Conclusion: Functional IL-18 gene polymorphisms do not influence the susceptibility to NPC in Tunisians but may contribute to disease onset and aggressiveness.     

Kinetic analyses for bindings of concanavalin A to dispersed and condensed mannose surfaces on a quartz crystal microbalance

A biotinylated mannotriose (Man3-bio) was dispersively immobilized in the matrix of biotinylated lactose (Gal-Glc-bio) on a streptavidin-covered, 27-MHz quartz crystal microbalance (QCM), and binding kinetics of concanavalin A (Con A) to Man3-bio in the Gal-Glc-bio matrix could be obtained from frequency decreases (mass increases) of the QCM. Association constants (K_a) and binding and dissociation rate constants (k_on and k_off) could be determined separately as the 1:1 and 1:2 bindings of Con A to Man3-bio on the surface. When Man3-bio was immobilized with content of 1 to 5 mol% in the matrix, the 1:1 binding of Con A to Man3-bio was obtained as K_a = (4 ± 1) × 10⁶ M⁻¹, k_on = (4 ± 1) × 10⁴ M⁻¹ s⁻¹, and k_off = (12 ± 2) × 10^–3 s⁻¹. On the contrary, when Man3-bio was immobilized with content of 20 to 100 mol% in the matrix, the 1:2 binding of Con A to Man3-bio was obtained as K_a = (14 ± 2) × 10⁶ M⁻¹, k_on = (14 ± 2) × 10⁴ M⁻¹ s⁻¹, and k_off = (7 ± 2) × 10^–3 s⁻¹. Thus, K_a for the 1:2 binding was 10 times larger than that for the 1:1 binding, with a three times larger binding rate constant (k_on) and a three times smaller dissociation rate constant (k_off). This is the first example to obtain separate kinetic parameters for the 1:1 and 1:2 bindings of lectins to carbohydrates on the surface.     

Clicker increases resistance to extinction but does not decrease training time of a simple operant task in domestic dogs (Canis familiaris)

Despite its popularity among pet owners and professional trainers, we are not aware of any studies that have investigated the efficacy of clicker training in canines. To this end, we taught 35 basenjis to nose-touch an orange traffic cone. Upon meeting pre-determined criteria, dogs progressed through: (1) training trials, wherein correct responses were followed immediately with a click plus food (clicker group) or food alone (control group); (2) strengthening trials, wherein dogs received the same reinforcement protocol as in training trials, except nose-touching behaviour was variably reinforced; and (3) extinction trials, wherein food was withheld from both groups, but dogs in the clicker group received a click alone for nose-touches. We found that the clicker and control groups did not differ with regard to the number of trials or the time required to meet training or strengthening criteria (P > 0.05 for all). However, the clicker group required significantly more trials (log₁₀ transformed means ± S.E. = 1.6 ± 0.03 trials versus 1.4 ± 0.03 trials, P < 0.001) and more time (log₁₀ transformed means ± S.E. = 2.85 ± 0.03 s versus 2.73 ± 0.03 s, P = 0.008) to reach extinction criterion. Additionally, younger dogs required fewer training (, P = 0.001) and strengthening (, P = 0.029) trials and less training (, P = 0.005) and strengthening (, P = 0.013) time to meet criteria than did older dogs. However, no age effect was found on extinction for either the number or duration of trials (P > 0.05 for both), implying that persistence in previously reinforced behaviour did not influence the age sensitivity found in task acquisition. Overall, these results suggest that, whereas the clicker may prolong behaviour without primary reinforcement, it does not reduce the training time of a simple operant task in dogs when primary reinforcement is briefly delayed. We speculate that the clicker may be most useful in maintaining established behaviours when primary reinforcement is unavailable or when its delivery is impractical. Additionally, we found that basenji dogs may become progressively impaired with age in the acquisition of stimulus-reward contingencies.     

The protective effect of selenium inorganic forms against cadmium and silver toxicity in mycelia of Pleurotus ostreatus

The effect of two inorganic selenium forms has been investigated in the mycelia of Pleurotus ostreatus exposed to cadmium and silver salts in the shaken cultures. The degree of toxicity was assessed by the determination of malondialdehyde (MDA; a common biomarker of lipid peroxidation). The mycelia were exposed to one element form (up to 5 mg l⁻¹) and also to the following combinations: cadmium(II) + selenium(IV); cadmium(II) + selenium(VI); silver(I) + selenium(IV); silver(I) + selenium(VI). The concentrations of cadmium, silver, selenium, and MDA were assessed in the mixed cytosol and cell membrane fractions (CCM). A positive correlation between MDA and cadmium was found in the CCM (β = 0.7775, P = 0.0001), whereas the effect of silver was less significant (β = 0.4642, P = 0.039). These results indicate that silver(I) and cadmium(II) have different capacities to induce lipid peroxidation in P. ostreatus. The protective role of selenium against metal-induced oxidative damage was found to be dependent on the oxidation state of the element form in the growth medium. The strongest beneficial effect was observed in mycelia exposed to cadmium(II) + selenium(IV) (inverse correlation between MDA and selenium in the CCM: β = −0.7129, P = 0.009) and it has been ascribed to a lower incorporation of the toxic metal and/or to possible intracellular interaction between selenium and cadmium. Under exposure to silver(I), the protective effect of selenium(IV) was less noticeable (correlation between MDA and selenium in the CCM; β = −0.6068, P = 0.036); in the presence of selenium(VI), no beneficial effect was observed.     

Interrelationships among morphology, echotexture, and function of the bovine corpus luteum during the estrous cycle

It has been suggested that ultrasound image attributes are a potential indicator of physiological and functional status of the corpus luteum (CL) in several species, including cattle. The aims of this study were to evaluate CL morphological, functional and echotextural characteristics, and also to investigate the hypothesis that those attributes are correlated and change similarly throughout an estrous cycle. Ovaries of crossbred (Bos taurus taurus × Bos taurus indicus) heifers were evaluated using ultrasonography daily throughout an interestrus interval using a B-mode, real-time ultrasound machine equipped with a 5 MHz linear-array rectal transducer, during a natural estrous cycle (Experiment 1; n = 12) or during a shortened cycle, with luteolysis induction 10 d after estrus (Experiment 2; n = 6). Blood samples were collected for assay of plasma progesterone concentrations. Corpora lutea areas were measured and daily images of each CL were videotaped and digitized for computer-assisted analysis using custom-developed software. In Experiment 1, area of luteal tissue increased until a maximum value 10 d after estrus (P < 0.001), followed by a plateau phase, and then a decline beginning 14 d after estrus. Luteal tissue area was highly correlated to plasma progesterone concentrations (r = 0.86; P < 0.001). When luteolysis was induced in Experiment 2, loss of CL function (decrease in plasma progesterone concentrations to metestrous values) preceded tissue regression by 48 h (24 h compared with 72 h; P < 0.001). The mean pixel value of ultrasound images did not change in Experiment 1 (P > 0.70), but a day effect on this attribute was observed in Experiment 2 (P = 0.052). In contrast, mean pixel value was correlated to plasma progesterone concentrations in Experiment 1 (r = −0.63; P < 0.05), but not in Experiment 2 (r = −0.28; P > 0.10). In regard to CL heterogeneity, defined as the standard deviation of the mean pixel value of the luteal tissue, a time effect was observed following both natural (Experiment 1; P < 0.009) and luteolysis-induced (Experiment 2; P < 0.05) estrous cycles (P < 0.05). Moreover, this variable was correlated with plasma progesterone concentrations (r = −0.71 and −0.58 in Experiments 1 and 2, respectively; P < 0.01), indicating that CL images were more heterogeneous during metestrus and after luteolysis (functional regression). In summary, morphological and echotextural attributes were correlated with CL function and underwent similar changes during the estrous cycle. Luteal tissue heterogeneity, assessed by ultrasonography, is considered a potential indicator of CL functional status, because it is correlated to circulating progesterone concentrations.     

Asymptotic theory for analyzing dose-response survival data with application to the low-dose extrapolation problem

A model of the form P(t, d)=1−;exp{-(t)σ^K_i=0q_idⁱ}, q_i 0, is proposed for analyzing dose-response survival data with right censoring. The q_i's in the dose polynomial are estimated by maximizing the Cox partial likelihood, and given these estimates. Λ(t) is estimated nonparametrically by an estimator proposed by Breslow. Large-sample properties of these estimators are established. Estimates and related large-sample properties are provided for the “virtually safe dose” and other parameters for assessing low-dose carcinogenic risk as a function of age, using data from animal carcinogenesis experiments.     

Molecular screening of interleukin-6 gene promoter and influence of −174G/C polymorphism on breast cancer

Interleukin-6 (IL-6) is a cytokine involved in different physiologic and pathophysiologic processes including carcinogenesis. In 2003, a single nucleotide polymorphism (−174G/C) of the IL-6 gene promoter has been linked to breast cancer prognosis in node-positive (N+) breast cancer patients. Since, different studies have led to conflicting conclusions about its role as a prognostic and/or diagnostic marker. The primary aim of our study was to investigate the link between −174G/C polymorphism and breast cancer risk on the one hand, and −174G/C polymorphism and prognosis in different groups of patients: sporadic N+ breast cancers (n = 138), sporadic N− breast cancers (n = 95) and familial breast cancer (n = 60) on the other hand. The variables of interest were disease-free survival and overall survival. The secondary aim of the study was to screen IL-6 gene promoter using direct sequencing to identify new polymorphisms in our French Caucasian breast cancer population. No association or trend of association between −174G/C polymorphism of IL-6 gene promoter gene and breast cancer diagnosis or prognosis was shown, even in meta-analyses. Furthermore, we have identified four novel polymorphic sites in the IL-6 gene promoter region: −764G → A, −757C → T, −233T → A, 15C → A.     

Influence of level of zilpaterol chlorhydrate supplementation on growth performance and carcass characteristics of feedlot lambs

Forty-eight Pelibuey × Katahdin (38.8 ± 0.67 kg) crossbred male lambs were used in a 32-day feeding trial (four pens per treatment in a randomized complete block design), to evaluate the influence of zilpaterol (β₂-agonist) supplementation level on growth performance and carcass characteristics. Lambs were fed a dry-rolled corn-based finishing diet (3.04 Mcal/kg of ME) supplemented with 0, 0.15, 0.20, or 0.25 mg/kg of live weight d⁻¹ zilpaterol (as zilpaterol chlorhydrate, Zilmax^®, Intervet México, México City). DM intake averaged 1.099 ± 0.042 kg/d and was not affected (P = 0.40) by treatments. Compared with control lambs, zilpaterol supplementation increased gain efficiency (15.8%, P < 0.03), apparent energy retention per unit DMI (10.9%, P = 0.03), and tended to increased daily gain (16%, P < 0.07) and total gain (17.7%, P < 0.08). Zilpaterol supplementation did not affect (P = 0.20) carcass weight, longissimus muscle area (LM), or fat thickness, but increased (2.3%, P = 0.04) carcass dressing percentage and reduced (36%, P < 0.01) kidney-pelvic fat. Increasing level of zilpaterol supplementation increased total weight gain (linear component, P < 0.05), gain:feed (linear component, P < 0.01), and dressing percentage (linear component, P < 0.02), and decreased (linear component, P < 0.01) kidney-pelvic fat. We conclude that zilpaterol supplementation enhances growth performance and dressing percentage in lambs in a manner comparable to that of cattle (greater muscle accretion, reduced body fat). Responses to zilpaterol was optimal when supplemented at 0.20 mg of zilpaterol/kg of live weight d⁻¹.     

Root health evaluation of three alfalfa varieties in Kerquin sandy land

Without a robust and healthy root system, establishment, productivity, and persistence are compromised. Consequently, research on alfalfa root morphology and health is very important in development of technology for efficient improvement and production of alfalfa. The objectives of this study were to evaluate the root morphology and health of three alfalfa varieties, Algonquin, Golden Queen, and Yellow Flower and to determine relationships among root morphology traits and root health. Yields from these varieties ranged from 5.83 to 43.93 t/ha, total root length ranged from 215.17 to 708.89 mm, root surface area from 124.95 to 468.37 cm², volume from 3.24 to 57.72 cm³, and forks from 1.25 × 10³ to 10.54 × 10³, and tips from 0.65 × 10³ to 3.17 × 10³. Root infestation score was negatively correlated with yield (r = ?0.997, P < 0.01), and was positively correlated with all root morphology traits (r = 0.466–0.997, P < 0.01), and yield was negatively associated with root morphology traits (r = ?0.755 to ?0.998, p < 0.01) with the exception of root tips (r = 0.448, P < 0.01). Results from these analyses indicated that root infestation score was the lowest averaged over age of alfalfa stand in Algonquin. Yield in 2-year old stands was greater in Golden Queen compared to the other two cultivars.     

Body size related adaptations of the avian myocardial phospholipid fatty acyl chain composition

The myocardial phospholipid fatty acid (FA) composition (mol %) of 7 avian species was determined, in a body mass range from 150 g (Japanese quail, Coturnix coturnix japonica) to 19 kg (turkey, Meleagris gallopavo). Significant allometric increases were found for C16:1 n7 (allometric exponent: B = 0.15), C18:1 n7 (B = 0.08), C18:1 n9 (B = 0.24), C20:1 n9 (B = 0.22) and C20:3 n3 (B = 0.12); moreover, total monounsaturates (B = 0.20) and the sum of n9 FAs (B = 0.24) was also positively related to body mass. The total n3 FAs (B = − 0.36), and within them C22:5 n3 (B = − 0.41) and C22:6 n3 (B = − 0.60) showed allometric declines, such as total polyunsaturated fatty acids (PUFA; B = − 0.01), unsaturation index (B = − 0.03) and mean FA chain length (B = − 0.003). Comparing our results with earlier published data on avian skeletal muscle and divergent mammalian tissues, the allometric scaling of the above membrane forming fatty acids seems to be part of a general relationship postulated as the theory “membranes as metabolic pacemakers”. In addition, the cardiac muscle malondialdehyde concentration was negatively related to body mass (B = − 0.16), referring to a lower level of lipid peroxidation in larger birds, and vice versa, indicating a progressive myocardial lipid peroxidation in smaller-bodied species.     

Physiological acclimation to light in Chara intermedia nodes

In this study we investigated the ability of Chara intermedia to acclimate to different irradiances (i.e. “low-light” (LL): 20–30 μmol photons m⁻² s⁻¹ and “high-light” (HL): 180–200 μmol photons m⁻² s⁻¹) and light qualities (white, yellow and green), using morphological, photosynthesis, chlorophyll fluorescence and pigment analysis.Relative growth rates increased with increasing irradiance from 0.016 ± 0.003 (LL) to 0.024 ± 0.005 (HL) g g⁻¹ d⁻¹ fresh weight and were independent of light quality. A growth-based branch orientation towards high-light functioning as a mechanism to protect the plant from excessive light was confirmed. It was shown that the receptor responsible for the morphological reaction is sensitive to blue-light.C. intermedia showed higher oxygen evolution (up to 10.5 (HL) vs. 4.5 (LL) nmol O₂ mg Chl⁻¹ s⁻¹), photochemical and energy-dependent Chl fluorescence quenching and a lower Fv/Fm after acclimation to HL. With respect to qP, the acclimation of the photosynthetic apparatus depended on light quality and needed the blue part of the spectrum for full development. In addition, pigment composition was influenced by light and the Chl a/Car and Antheraxanthin (A) + Zeaxanthin (Z)/Violaxanthin (V) + A + Z (DES) ratios revealed the expected acclimation behaviour in favour of carotenoid protection under HL (i.e. decrease of Chl a/Car from 3.41 ± 0.48 to 2.30 ± 0.35 and increase of DES from 0.39 ± 0.05 to 0.87 ± 0.03), while the Chl a/Chl b ratios were not significantly affected. Furthermore it was shown that morphological light acclimation mechanisms influence the extent of the physiological modifications.