Split digraphs

We generalize the class of split graphs to the directed case and show that these split digraphs can be identified from their degree sequences. The first degree sequence characterization is an extension of the concept of splittance to directed graphs, while the second characterization says a digraph is split if and only if its degree sequence satisfies one of the Fulkerson inequalities (which determine when an integer-pair sequence is digraphic) with equality.Comment: 14 pages, 2 figures; Accepted author manuscript (AAM) versio

Split Supersymmetry

The naturalness criterion applied to the cosmological constant implies a new-physics threshold at 10^-3 eV. Either the naturalness criterion fails, or this threshold does not influence particle dynamics at higher energies. It has been suggested that the Higgs naturalness problem may follow the same fate. We investigate this possibility and, abandoning the hierarchy problem, we use unification and dark matter as the only guiding principles. The model recently proposed by Arkani-Hamed and Dimopoulos emerges as a very interesting option. We study it in detail, analysing its structure, and the conditions for obtaining unification and dark matter.Comment: 29 pages, comments, corrections and references adde

Mini-Split

The lack of evidence for new physics beyond the standard model at the LHC points to a paucity of new particles near the weak scale. This suggests that the weak scale is tuned and that supersymmetry, if present at all, is realized at higher energies. The measured Higgs mass constrains the scalar sparticles to be below 10^5 TeV, while gauge coupling unification favors Higgsinos below 100 TeV. Nevertheless, in many models gaugino masses are suppressed and remain within reach of the LHC. Tuning the weak scale and the renormalization group evolution of the scalar masses constrain Split model building. Due to the small gaugino masses, either the squarks or the up-higgs often run tachyonic; in the latter case, successful electroweak breaking requires heavy higgsinos near the scalar sparticles. We discuss the consequences of tuning the weak scale and the phenomenology of several models of Split supersymmetry including anomaly mediation, U(1)_(B-L) mediation, and Split gauge mediation.Comment: 26 pages, 12 figures; v2:discussion and figure on the status of fine-tuning in SUSY added, pheno section extende

Oromandibular Dysfunction Among Dental Students

The aim of the study was to determine frequency of oromandibular dysfunction among dental students. A total of 186 second and third year students (131 women and 55 men) aged 19-31 years (M=23) were examined, using the Gerber System instrumental technique. Oromandibular dysfunction was diagnosed according to IHS and AAOP criteria. T-TH was found in 58% of students, occlusal parafunction in 58%, non-occlusal parafunction in 84%. Tooth numbness occurred in 20% of subjects, masticatory muscle soreness on palpation in 28%, muscle hypertrophy in 14%. TMJ acoustic sounds were noticed in 55% of students, TMJ pain in 31%, limited mandibular movement while opening the mouth in 37%. All students examined had premature occlusal contacts, they were asymmetric in 98%. Oromandibular dysfunction was diagnosed in 79%, 21% of which had 6 or more dysfunction signs and symptoms, 19% had only one or two of them. The Eysenck personality questionnaire, additionally used in the study, revealed different types of personalities among students. Conclusion: Oromandibular dysfunction symptoms were observed in most ofstudents. They should be associated with school induced stress and not with the personality type of the subjects examined