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2021 ◽  
Vol 12 ◽  
Author(s):  
Keri V. Langridge ◽  
Claudia Wilke ◽  
Olena Riabinina ◽  
Misha Vorobyev ◽  
Natalie Hempel de Ibarra

Gaze direction is closely coupled with body movement in insects and other animals. If movement patterns interfere with the acquisition of visual information, insects can actively adjust them to seek relevant cues. Alternatively, where multiple visual cues are available, an insect’s movements may influence how it perceives a scene. We show that the way a foraging bumblebee approaches a floral pattern could determine what it learns about the pattern. When trained to vertical bicoloured patterns, bumblebees consistently approached from below centre in order to land in the centre of the target where the reward was located. In subsequent tests, the bees preferred the colour of the lower half of the pattern that they predominantly faced during the approach and landing sequence. A predicted change of learning outcomes occurred when the contrast line was moved up or down off-centre: learned preferences again reflected relative frontal exposure to each colour during the approach, independent of the overall ratio of colours. This mechanism may underpin learning strategies in both simple and complex visual discriminations, highlighting that morphology and action patterns determines how animals solve sensory learning tasks. The deterministic effect of movement on visual learning may have substantially influenced the evolution of floral signals, particularly where plants depend on fine-scaled movements of pollinators on flowers.


2021 ◽  
Author(s):  
Gina Esther Merges ◽  
Julia Meier ◽  
Simon Schneider ◽  
Alexander Kruse ◽  
Andreas Christian Fröbius ◽  
...  

One of the key events during spermiogenesis is the hypercondensation of chromatin by substitution of the majority of histones by protamines. In humans and mice, protamine 1 (PRM1/Prm1) and protamine 2 (PRM2/Prm2), are expressed in a species-specific ratio. Using CRISPR-Cas9-mediated gene editing we generated Prm1-deficient mice and demonstrate, that Prm1+/- mice are subfertile while Prm1-/- are infertile. Prm1-deficiency was associated with higher levels of 8-OHdG, an indicator for reactive oxygen mediated DNA-damage. While Prm1+/- males displayed moderate increased levels of 8-OHdG virtually all sperm of Prm1-/- males displayed ROS mediated DNA damage. Consequently, DNA integrity was slightly hampered in Prm1+/-, while DNA was completely fragmented in Prm1-/- animals. Interestingly CMA3 staining which indicates protamine-free DNA revealed, that Prm1+/- sperm displayed high levels (93%), compared to Prm2+/- (29%) and WT (2%) sperm. This is not due to increased histone retention as demonstrated by mass spectrometry (MassSpec) of nuclear proteins in Prm1+/- sperm. Further analysis of the MassSpec data from sperm nuclear proteome revealed, that only one protein (RPL31) is significantly higher abundant in Prm1+/- compared to WT sperm. Comparison of the proteome from Prm1-/- and Prm2-/- to WT suggested, that there are a small number of proteins which differ in abundance. However, their function was not linked mechanistically to primary defects seen in Prm1-/- mice and rather represent a general stress response. Interestingly, using acid urea gels we found that sperm from Prm1+/- and Prm1-/- mice contain a high level of unprocessed, full-length PRM2. Prm2 is transcribed as a precursor protein which, upon binding to DNA is successively processed. Further, the overall ratio of PRM1:PRM2 is skewed from 1:2 in WT to 1:5 in Prm1+/- animals. Our results reveal that Prm1 is required for proper processing of PRM2 to produce the mature PRM2 which, together with Prm1 is able to hypercondense DNA. Hence, the species specific PRM1:PRM2 ratio has to be precisely controlled in order to retain full fertility.


2021 ◽  
Vol 11 (1) ◽  
pp. 7-13
Author(s):  
Umesh Parajuli ◽  
Alok Kumar Jaiswal ◽  
Manish Bajracharya ◽  
Manju Pandey ◽  
Sapna Laxmi Tuladhar

Introduction: The tooth size ratios may vary among different ethnic groups and different malocclusion groups. The objective of this study is to see the tooth size discrepancies in two major ethnic groups of Nepal; Indo-Aryans and Tibeto-Burmans and different malocclusion groups and compare it with the Bolton’s study. Materials and Method: The anterior and overall ratios were compared between Indo-Aryans and Tibeto-Burmans according to different malocclusion groups with Bolton’s study with one sample t-test. The differences in ratios in ethnic groups and gender were seen with one sample t-test. The differences in mesio-distal tooth width amongst the two ethnic groups were seen. One sample ANOVA was used to see any correlation between the ethnic groups and the different malocclusion groups. Result: The anterior ratio and overall ratio in Indo- Aryans and Tibeto-Burmans in all the malocclusion groups were greater than the Bolton’s study but was not statistically significant. There was significant differences in anterior ratio between Indo-Aryans (77.63 + 2.74%) and Tibeto-Burmans (78.51 + 2.76%), p value= 0.024. There were no statistical significant differences in the anterior and overall ratio amongst males and females. The mesio-distal tooth size was greater in Tibeto-Burmans as compared to Indo-Aryans expect for maxillary right and left central incisors. Conclusion: The Tibeto-Burmans had higher anterior ratio as compared to Indo-Aryans. The Tibeto-Burmans had broader teeth as compared to Indo-Aryans except for maxillary central incisors.


2021 ◽  
Vol 104 (3) ◽  
pp. 003685042110381
Author(s):  
Beyza Karadede Ünal ◽  
Deniz Dellaloğlu

Objective: It is aimed to examine the tooth sizes of digital models of patients with different malocclusions with the help of three-dimensional measurement software. Methods: Digital models of 252 patients aged between 13 and 25 years of age were included. According to the Angle classification, three different malocclusion groups were allocated such that there were 84 patients in each group, plaster models of patients scanned with the three-dimensional model browser 3Shape R700 3D Scanner (3Shape A/S Copenhagen, Denmark) and transferred to the digital format. 3Shape Ortho Analyzer (3Shape A/S Copenhagen, Denmark) software was used for making the necessary tooth size measurements. Results: When the measurements were evaluated, it was determined that significant changes occurred between tooth sizes of individuals with different malocclusions. Generally, higher values were observed in mesiodistal and buccolingual tooth dimensions of class II individuals compared to other groups. There was no difference between the groups in the anterior ratio values, but when the overall ratio values were evaluated among the groups, a statistically significant difference was determined. Class II malocclusion group was found to have a significantly lower overall ratio of occurrence. Conclusion: Individuals with different malocclusions differ in tooth size.


2021 ◽  
Vol 12 ◽  
Author(s):  
Ryo Matsuda ◽  
Hiroki Ito ◽  
Kazuhiro Fujiwara

The effects of photosynthetic photon flux density (PPFD) fluctuations in sunlight have already been investigated; however, the spectral photon flux density distribution (SPD) has hardly been considered. Here, sunlight SPD fluctuations recorded for 200 min in October in Tokyo, Japan were artificially reproduced using an LED-artificial sunlight source system. The net photosynthetic rate (Pn) of cucumber leaves under reproduced sunlight was measured and compared with the Pn estimated from a steady-state PPFD–Pn curve for the same leaves. The measured and estimated Pn agreed except when the PPFD was low, where the measured Pn was lower than the estimated Pn. The ratio of measured Pn to estimated Pn was 0.94–0.95 for PPFD ranges of 300–700 μmol m–2 s–1, while the value was 0.98–0.99 for 900–1,300 μmol m–2 s–1, and the overall ratio was 0.97. This 3% reduction in the measured Pn compared with the Pn estimated from a steady-state PPFD–Pn curve was significantly smaller than the approximately 20–30% reduction reported in previous experimental and simulation studies. This result suggests that the loss of integral net photosynthetic gain under fluctuating sunlight can vary among days with different fluctuation patterns or may be non-significant when fluctuations in both PPFD and relative SPD of sunlight are taken into consideration.


2021 ◽  
Author(s):  
Yoshiyuki Senga ◽  
Akinobu Nishimura ◽  
Naoya Ito ◽  
Yukie Kitaura ◽  
Akihiro Sudo

Abstract Background: Hallux rigidus (HR) is a common degenerative arthritis of the first metatarsophalangeal joint. However, the epidemiology and risk factors of this pathology have yet to be clarified.Methods: This cohort study estimated the prevalence of and clarified risk factors for radiographic HR in individuals over 50 years old.Results: The prevalence of HR was 26.7% (161/604). Rates of grade 0, 1, 2, and 3 HR according to the Hattrup and Johnson classification were 73.3% (443/604), 16.4% (99/604), 8.0% (48/604), and 2.3% (14/604), respectively. Overall ratio of symptomatic HR was 8.1%. Univariate analysis revealed knee osteoarthritis (KOA), gout attack (GA), and hallux valgus (HV) as significantly associated with HR. The same factors were confirmed as independent risk factors for HR in multivariate analysis. All parameters were significantly associated with HR. Odds ratios of KOA, HV, and GA for HR were 1.73, 3.98, and 3.86, respectively. The presence or absence of KOA was significantly associated with severity of HR.Conclusion: Our study revealed the prevalence of HR in the elderly (≥50 years) was 26.7%, and KOA, HV, and GA were independent risk factors for HR. KOA was associated with severity of HR.


Author(s):  
Muhammad Faraz Jokhio ◽  
Ghazanfar Ali Shah ◽  
Raheel Akbar Baloch ◽  
Mohsin Aijaz Soomro ◽  
Najeeb Ur Rehman ◽  
...  

Non-union infected bone is a chronic impairment disorder that causes severe complications for surgeons. In Pakistan a very limited literature was produced in recent years to evaluate the role of antibiotic impregnated cemented nail in infected non-union of tibia. To fill this gap this prospective study was designed to investigate the role of antibiotic Cement Coated Nailing in Infected Nonunion of Tibia in the Orthopedic Department of Liaqat University of medical and health science, Jamshoro, Pakistan, from February 2019 to February 2020. A total of 30 patients with infected "nonunion of the tibia" was enrolled during the research period. Patients within the age range of 22-61 years were part of this research. For surgery, polymer beads were added into the 40 gm cement which was prepared by adding 2 gm vancomycin and 2 gm teicoplanin. After that endotracheal tube was cut by a surgical knife to recover antibiotic and cement coated k nail. The nail was then inserted into the tibia. Resuts demonstrate that in 28 patients 93% utilization of antibodies cement coated nails helped to eradicate the infection. 24 patients achieved complete bone unification without any need for further procedure. The overall ratio of single-time antibiotic cement coated nail was observed as 70%. The infected nonunion tibia can be effectively treated if the protocol of debridement is correctly followed. Results demonstrate that bone stability can be regained with 22 to 44 weeks. We concluded that antibiotic-impregnated cemented nail is an ideal procedure to control the postoperative infection and achieve reunion.


2021 ◽  
Vol 69 (2) ◽  
pp. 649-664
Author(s):  
Blanca Martínez ◽  
René López Camacho ◽  
Luis Santiago Castillo ◽  
Rodrigo Bernal

Introduction: Understanding the phenology of plant populations is vital for their conservation and management. We studied the vegetative and reproductive phenology of the endangered palm Ceroxylon quindiuense along an altitudinal gradient in the Central Cordillera of Colombia. Objective: We describe the leaf production rate, and flowering and fruiting cycles, and calculate food offer for the fauna, as a tool for the proper management of the palm. Methods: At each sampling site (2 400, 2 600, 2 800, 3 000 m.a.s.l.), we marked 40 adult individuals (20 pistillate, 20 staminate), which we followed bimonthly for 24 months. We studied leaf production by counting fallen leaves. We followed flower and fruit production through observations with binoculars and photographs. Results: Each adult individual produced, on average, one leaf every 61 days. Although isolated individuals flowered throughout the year, most palms flowered synchronously at each elevation in October 2016-August 2017 and in August 2018-February 2019 and had ripe fruits 7-13 months later. Flowering started at 2 600 m, followed by 2 800 and 3 000 m. Palms at 2 400 m, the lower limit of the palm stands in the area, showed a singular behavior, with scarce flower and fruit production, some individuals that changed sex, and a higher proportion of pistillate palms. Each palm produced 1-11 (x̄ = 5.3, SD = 2.2) inflorescences and 1-10 (x̄ = 5.3, SD = 2.2) infructescences. The average number of fruits per infructescence was 4 465 (SD = 1 488). With an estimated population of adult palms between 256 000 and 600 000 and an overall ratio of pistillate: staminate individuals 1:1 or 1:2, total fruit production in the area during each fruiting period is estimated as 2.0-7.1 billion fruits. Conclusions: The huge number of flowers and fruits and their gradual availability along the altitudinal gradient have a major impact on the spatial and temporal distribution of food offer for fauna associated with the palm.


2021 ◽  
Vol 24 (2) ◽  
Author(s):  
Raja AbdAlgadir Mustafa ◽  
Amal Hussein Abuaffan

Introduction: A correct proportion between the upper and lower teeth is critical to achieving proper occlusal interdigitation, ideal overjet, and good molar intercuspation at the end of orthodontic treatment. Objectives: To determine the anterior and overall Bolton’s ratio in the Sudanese population, investigate gender differences in tooth size ratios, and to compare these results with Bolton’s original ratio norm. Material and Methods: The sample consisted of dental casts of 104 Sudanese University students with normal occlusion (52 females, 52 males), aged between 16-26 years randomly selected from AL- Neelain University. An electronic digital caliper was used to measure the mesiodistal tooth size of the maxillary and mandibular teeth anterior to the second molars. These measurements were then used to obtain Bolton’s ratio. Mean, range, and standard deviation of the anterior and overall ratios were computed for each subject. T-Tests were used to compare gender differences and to investigate differences between the results of this study and Bolton’s original ratio. Results: Anterior and overall Bolton ratios for males were 78.43±2.44 and 93.901±9.8 and for females were 78.29±2.6 and 91.67±3.3 percent, respectively. There were no statistically significant differences between males and females for the anterior and overall ratios P>0.05. The anterior and overall Bolton’s ratios among Sudanese University students were 78.37 ± 2.54, and 92.79± 7.43 percent, respectively. statistically significant difference between this study and Bolton’s study were found in both anterior and overall ratio P<0.05. Conclusion: Bolton’s mean ratios may not be applicable to Sudanese. Keywords Bolton’s ratio; Sudanese population; tooth-size.


2021 ◽  
Author(s):  
A. D. Grabowska ◽  
N. Andreu ◽  
T. Cortes

Abstract Mycobacterium tuberculosis expresses a large number of leaderless mRNA transcripts; these lack the 5’ leader region, which usually contains the Shine-Dalgarno sequence required for translation initiation in bacteria. In M. tuberculosis, transcripts encoding proteins with secondary adaptive functions are predominantly leaderless and the overall ratio of leaderless to Shine-Dalgarno transcripts significantly increases during growth arrest, suggesting that leaderless translation might be important during persistence in the host. However, whether these two types of transcripts are translated with differing efficiencies during stress conditions that induce growth arrest and during optimal growth conditions, is unclear. Here, using bioluminescent reporter strains, we detect robust leaderless translation during exponential in vitro growth and we show that leaderless translation is more stable than Shine-Dalgarno translation during adaptation to stress conditions. Upon entrance into nutrient starvation and after nitric oxide exposure, leaderless translation is significantly less affected by the stress than Shine-Dalgarno translation. Similarly, during the early stages of infection of macrophages, the levels of leaderless translation are more stable than those of Shine-Dalgarno translation. These results suggest that leaderless translation may offer an advantage in the physiology of M. tuberculosis. Identification of the molecular mechanisms underlying this translational regulation may provide insights into persistent infection.


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