Gingival thickness in dogs: association with age, gender, and dental arch location

Reduced gingival thickness is one of many factors that might predispose humans to periodontal disease and subsequent gingival recession. Gingival thickness differs between individuals, and is associated with age, gender, and location on the dental arch. Different gingival phenotypes exist in the human population according to the thickness of gingiva. Similar information on gingival phenotypes in dogs is unknown. The aim of this study was to investigate the thickness of the gingiva in dogs and its relation to age, gender and location on the dental arch. For this study, 48 dogs of comparable size (40-cm at withers) were divided into three groups according to their age as follows: < 2-years of age; 2 to 8-years of age; > 8-years of age. Gingival thickness was measured in both the mandible and maxilla using a transgingival probing technique. The graded probe was inserted midway into the attached gingiva at the level of each tooth class region. Young and middle aged dogs had significantly thicker gingiva (1.67 +/- 0.17 mm and 1.68 +/- 0.18 mm, respectively) compared with older dogs (1.54 +/- 0.16 mm). There was no significant difference in gingival thickness based on location or gender Generally, the gingiva was thicker at the level of large teeth such as canine and carnassial teeth. Regions of thinner gingiva at the level of incisor and premolar teeth correlated with the regions of highest prevalence of periodontal disease found in previous studies.     

Acrosomal and viability status of bovine spermatozoa evaluated by two staining methods

Artificial insemination with frozen-thawed spermatozoa is commonly used in cattle breeding. A simple and fast procedure is needed for routine evaluation of the acrosomal status of frozen-thawed bovine sperm. Therefore, the purpose of this study was to test two staining procedures used to determine the viability and integrity of acrosome of frozen-thawed bovine spermatozoa. Double staining and Hoechst/FITC-Pisum sativum agglutinin (FITC-PSA) labelling were tested for evaluating the viability and acrosome reaction induced by calcium ionophore of bull spermatozoa. In our experiments no significant differences were detected in the frequency of acrosome-reacted sperm either by double staining (37.98%) or by FITC-PSA labelling (39.33%). The viability of sperm stained by the double staining method was 67.17%, and a higher portion of viable sperm (82.67%) was observed by staining with the Hoechst procedure (P < 0.01). On the basis of the results obtained it is concluded that both methods can be used for detecting the acrosome reaction of frozen-thawed bovine spermatozoa.     

Conservation implications of establishment success of the Critically Endangered Twee River redfin ‘Pseudobarbus’ erubescens (Skelton, ) in an artificial impoundment in South Africa

相似文献   

To Join Small-Scale Forest Owners’ Associations or Not? Motivations and Opinions of Small-Scale Forest Owners in Three Selected Regions of the Czech Republic

This article analyses motivations and attitudes of small-scale forest owners in the Czech Republic towards joining associations. The research is a follow-up to a field investigation performed within the National Forest Programme II for 2007–2013 in the Vyso?ina region in 2010. The present research was carried out in the Pilsen region in 2012 and the Central Bohemia region in 2015, applying the same method of investigation as in 2010—a questionnaire survey. The findings are based on the results of all three surveys and supported by the analysis of legal and forestry-related documents concerning financial subsidies for forest owners’ associations. The study has revealed reluctance of small-scale owners to join associations. Their lack of motivation is caused by insufficient funding from the government supporting the administration and management of associations. The reluctance also results from the request for associations to be legal entities, which most applicants do not meet as they are either not registered or are registered under unsuitable legal forms. Between 2011 and 2013, no contributions were paid by the government to associations, and no new small-scale forest owners’ associations were formed. To increase associations, we propose that the government should provide sufficient funding not only for the administration and management of associations but also for the process of establishing associations and initial investments. It is also necessary to make major innovations in legislature regarding the transition of ownerships to more convenient legal forms.     

Improving Estimates of Fried’s Index from Mating Competitiveness Experiments

Sterile insect technique (SIT) and incompatible insect technique (IIT) are current methods for biological control of insect populations. Critical to the successful implementation of these biocontrol programs is quantifying the competitiveness of sterile/incompatible male insects for female mates relative to wildtype males. Traditionally, entomologists measure this mating competitiveness through a quantity known as Fried’s Index. We establish that Fried’s Index is mathematically equivalent to the mating competitiveness coefficient that features in many population models used in SIT/IIT programs. Using this insight, we propose a new approach for estimating Fried’s Index from mating competitiveness experiments. We show that this approach offers greater precision and accuracy than the traditional approach that is currently used in many studies. This is demonstrated using both simulation experiments and by analysing real experimental data. To facilitate uptake of the proposed method, we also provide an R package that can be used to easily analyse data from mating competitiveness experiments.     

Rodents as intermediate hosts of Hepatozoon ayorgbor (Apicomplexa: Adeleina: Hepatozoidae) from the African ball python, Python regius?

Two experimental trials were performed to elucidate the role of rodents in the life cycle of Hepatozoon species using snakes as intermediate hosts. In one trial, two ball pythons, Python regius Shaw, 1802 were force fed livers of laboratory mice previously inoculated with sporocysts of Hepatozoon ayorgbor Sloboda, Kamler, Bulantová, Votypka et Modry, 2007. Transmission was successful in these experimentally infected snakes as evidenced by the appearance of intraerythrocytic gamonts, which persisted until the end of trial, 12 months after inoculation. Developmental stages of haemogregarines were not observed in histological sections from mice. In another experimental trial, a presence of haemogregarine DNA in mice inoculated with H. ayorgbor was demonstrated by PCR in the liver, lungs and spleen.     

Nitrogen and winter cover crop effects on spring and summer nutrient uptake

Overseeded winter annuals in bermudagrass [Cynodon dactylon (L.) Pers.] improve annual dry‐matter (DM) yield and capture nutrients in fields receiving manure application. This study determined the DM and nutrient uptake responses of annual ryegrass (Lolium multiflorum L.), cereal rye (Secale cereale), berseem clover (Trifolium alexandrinum L.) and bermudagrass‐winter fallow to 0, 50, 100 and 150 kg N ha^?1 applied approximately 2 months before a single spring harvest, and in addition to swine‐effluent N (258 and 533 kg ha^?1 in summer 2000 and 2001, respectively). Under drought conditions in 2000, DM yield at the spring harvest was highest in ryegrass, and summer DM yield of bermudagrass was greater at 100 and 150 kg N ha^?1 than 50 kg N ha^?1(P < 0·05). The concentration and uptake of N at the spring harvest increased linearly across N rates in both years (P < 0.05). Cover crops differed in N uptake in 2000 (P < 0.01) and values ranged from approximately 141 kg N ha^?1 in berseem clover to 86 kg N ha^?1 in rye. Per unit of N applied, uptake of N increased by approximately 0·409 kg ha^?1 in 2000 and 0·267 kg ha^?1 in 2001; uptake of P increased by 0·029 and 0·014 kg ha^?1 respectively. In 2000, uptake of P was responsive to N rate and this relationship was significant (P < 0·01) in winter fallow (slope = 0·032) and ryegrass (slope = 0·057). Increased uptake of N and P at the single spring harvest was due mainly to higher concentrations in herbage and not higher DM yield.