The Tree Inclusion Problem: In Linear Space and Faster

Given two rooted, ordered, and labeled trees $P$ and $T$ the tree inclusion problem is to determine if $P$ can be obtained from $T$ by deleting nodes in $T$. This problem has recently been recognized as an important query primitive in XML databases. Kilpel\"ainen and Mannila [\emph{SIAM J. Comput. 1995}] presented the first polynomial time algorithm using quadratic time and space. Since then several improved results have been obtained for special cases when $P$ and $T$ have a small number of leaves or small depth. However, in the worst case these algorithms still use quadratic time and space. Let $n_S$, $l_S$, and $d_S$ denote the number of nodes, the number of leaves, and the %maximum depth of a tree $S \in \{P, T\}$. In this paper we show that the tree inclusion problem can be solved in space $O(n_T)$ and time: O(\min(l_Pn_T, l_Pl_T\log \log n_T + n_T, \frac{n_Pn_T}{\log n_T} + n_{T}\log n_{T})). This improves or matches the best known time complexities while using only linear space instead of quadratic. This is particularly important in practical applications, such as XML databases, where the space is likely to be a bottleneck.Comment: Minor updates from last tim

An Expert Consensus Statement on the Management of Large Chondral and Osteochondral Defects in the Patellofemoral Joint

© The Author(s) 2020. Background: Cartilage lesions of the patellofemoral joint constitute a frequent abnormality. Patellofemoral conditions are challenging to treat because of complex biomechanics and morphology. Purpose: To develop a consensus statement on the functional anatomy, indications, donor graft considerations, surgical treatment, and rehabilitation for the management of large chondral and osteochondral defects in the patellofemoral joint using a modified Delphi technique. Study Design: Consensus statement. Methods: A working group of 4 persons generated a list of statements related to the functional anatomy, indications, donor graft considerations, surgical treatment, and rehabilitation for the management of large chondral and osteochondral defects in the patellofemoral joint to form the basis of an initial survey for rating by a group of experts. The Metrics of Osteochondral Allografts (MOCA) expert group (composed of 28 high-volume cartilage experts) was surveyed on 3 occasions to establish a consensus on the statements. In addition to assessing agreement for each included statement, experts were invited to propose additional statements for inclusion or to suggest modifications of existing statements with each round. Predefined criteria were used to refine statement lists after each survey round. Statements reaching a consensus in round 3 were included within the final consensus document. Results: A total of 28 experts (100% response rate) completed 3 rounds of surveys. After 3 rounds, 36 statements achieved a consensus, with over 75% agreement and less than 20% disagreement. A consensus was reached in 100.00% of the statements relating to functional anatomy of the patellofemoral joint, 88.24% relating to surgical indications, 100.00% relating to surgical technical aspects, and 100.00% relating to rehabilitation, with an overall consensus of 95.5%. Conclusion: This study established a strong expert consensus document relating to the functional anatomy, surgical indications, donor graft considerations for osteochondral allografts, surgical technical aspects, and rehabilitation concepts for the management of large chondral and osteochondral defects in the patellofemoral joint. Further research is required to clinically validate the established consensus statements and better understand the precise indications for surgery as well as which techniques and graft processing/preparation methods should be used based on patient- and lesion-specific factors

An Arthroscopic Device to Assess Articular Cartilage Defects and Treatment with a Hydrogel

The hydraulic resistance R across osteochondral tissue, especially articular cartilage, decreases with degeneration and erosion. Clinically useful measures to quantify and diagnose the extent of cartilage degeneration and efficacy of repair strategies, especially with regard to pressure maintenance, are still developing. The hypothesis of this study was that hydraulic resistance provides a quantitative measure of osteochondral tissue that could be used to evaluate the state of cartilage damage and repair. The aims were to (1) develop a device to measure R in an arthroscopic setting, (2) determine whether the device could detect differences in R for cartilage, an osteochondral defect, and cartilage treated using a hydrogel ex vivo, and (3) determine how quickly such differences could be discerned. The apparent hydraulic resistance of defect samples was ~35% less than intact cartilage controls, while the resistance of hydrogel-filled groups was not statistically different than controls, suggesting some restoration of fluid pressurization in the defect region by the hydrogel. Differences in hydraulic resistance between control and defect groups were apparent after 4 s. The results indicate that the measurement of R is feasible for rapid and quantitative functional assessment of the extent of osteochondral defects and repair. The arthroscopic compatibility of the device demonstrates the potential for this measurement to be made in a clinical setting

NT2 Derived Neuronal and Astrocytic Network Signalling

A major focus of stem cell research is the generation of neurons that may then be implanted to treat neurodegenerative diseases. However, a picture is emerging where astrocytes are partners to neurons in sustaining and modulating brain function. We therefore investigated the functional properties of NT2 derived astrocytes and neurons using electrophysiological and calcium imaging approaches. NT2 neurons (NT2Ns) expressed sodium dependent action potentials, as well as responses to depolarisation and the neurotransmitter glutamate. NT2Ns exhibited spontaneous and coordinated calcium elevations in clusters and in extended processes, indicating local and long distance signalling. Tetrodotoxin sensitive network activity could also be evoked by electrical stimulation. Similarly, NT2 astrocytes (NT2As) exhibited morphology and functional properties consistent with this glial cell type. NT2As responded to neuronal activity and to exogenously applied neurotransmitters with calcium elevations, and in contrast to neurons, also exhibited spontaneous rhythmic calcium oscillations. NT2As also generated propagating calcium waves that were gap junction and purinergic signalling dependent. Our results show that NT2 derived astrocytes exhibit appropriate functionality and that NT2N networks interact with NT2A networks in co-culture. These findings underline the utility of such cultures to investigate human brain cell type signalling under controlled conditions. Furthermore, since stem cell derived neuron function and survival is of great importance therapeutically, our findings suggest that the presence of complementary astrocytes may be valuable in supporting stem cell derived neuronal networks. Indeed, this also supports the intriguing possibility of selective therapeutic replacement of astrocytes in diseases where these cells are either lost or lose functionality

Short-Term Enrichment Makes Male Rats More Attractive, More Defensive and Alters Hypothalamic Neurons

Innate behaviors are shaped by contingencies built during evolutionary history. On the other hand, environmental stimuli play a significant role in shaping behavior. In particular, a short period of environmental enrichment can enhance cognitive behavior, modify effects of stress on learned behaviors and induce brain plasticity. It is unclear if modulation by environment can extend to innate behaviors which are preserved by intense selection pressure. In the present report we investigate this issue by studying effects of relatively short (14-days) environmental enrichment on two prominent innate behaviors in rats, avoidance of predator odors and ability of males to attract mates. We show that enrichment has strong effects on both the innate behaviors: a) enriched males were more avoidant of a predator odor than non-enriched controls, and had a greater rise in corticosterone levels in response to the odor; and b) had higher testosterone levels and were more attractive to females. Additionally, we demonstrate decrease in dendritic length of neurons of ventrolateral nucleus of hypothalamus, important for reproductive mate-choice and increase in the same in dorsomedial nucleus, important for defensive behavior. Thus, behavioral and hormonal observations provide evidence that a short period of environmental manipulation can alter innate behaviors, providing a good example of gene-environment interaction

The Impact of Target-Group-Specific Metaphorical Headlines on a Direct Mail’s Advertising Effect: An Exploratory Mixed Methods Approach.

Purpose of the Study This study’s purpose is to analyse the influence of a metaphor’s persuasive effects on a direct mail’s advertising effect - and by doing to so close a research gap, as until now research concerning the effects of metaphors used in promotional communication has been restricted to print advertising. State of Knowledge Even though theory suggests manifold effects of metaphors on recipients, the research conducted so far in this field of interest shows inconsistent results: although metaphors seem to be able to affect e. g. a recipient’s attention, attitude or behavioural intentions, the use of metaphors is by no means a warrantor for persuasive effects. The Approach of Tarqet-qroup-specificity On closer examination of the subject’s extant knowledge, the underlying research identified certain moderating variables that can be suggested to influence a metaphor’s effects on recipients. As most of the moderators can be assumed to be dependent on the underlying target group, the approach of target-group-specificity has come into existence - suggesting, that the findings’ inconsistencies result from the tested metaphors’ different levels of target-group-specificity. Furthermore, the approach of target-group-specificity has been expanded from the issue of metaphor to the test scenario as a whole: to test the advertising effect of a metaphor does not only imply to account for a metaphor’s moderators to become more relevant for the target group but also to embed this target-group-specific metaphor in a target-group-specific promotional communication, which is then evaluated by the underlying target group. Course of Action and Findings 1st stage: Qualitative Development of the target-group-specific Elements Firstly, the needed information to develop the target-group-specific metaphor, the product as well the mailing has been worked out within a qualitative focus group consisting of target group members. Furthermore, a qualitative approach was designed to develop metaphors with different levels of target-group-specificity. Here, a non-, a less- and a target-group-specific metaphor as well as a target-group-specific literal equivalent were defined. 2nd stage: Quantitative Testing of the variably specific Metaphors Secondly, three headlines consisting of the three qualitatively developed metaphors were quantitatively evaluated by the target group. The recipients rated the different headlines’ aptness to promote the product developed within the focus group and decided in favour of the target-group-specific metaphorical headline - with the less-and non-significant versions taking the second and third place. 3rd stage: Quantitative Testing of Mailings containing different Metaphors Thirdly, the three tested headlines as well as a fourth target-group-specific literal headline were included into a target-group-specific mailing. The target group evaluated the four different mailings concerning their advertising effect. Given this, the mailing containing the target-group-specific metaphorical headline took the leading position. However, the comparison of the other three mailings did not indicate any significant differences. Implications Hence, the research question can be answered in the affirmative: there is a difference between direct mails that use target-group-specific metaphorical headlines and those that use none concerning their advertising effect - as target-group-specific metaphorical headlines seem to increase a direct mail’s advertising effect compared to less specific metaphorical as well as target-group-specific literal headlines. However, next to the fact that this thesis closed a research gap by expanding metaphor research to the field of direct marketing, it becomes apparent that it also opens up a new research field by inventing the thesis’ fundamental basis: the approach of target-group-specificity. It is this approach, i. e. , the need for target-group-specific metaphors applied to target-group-specific products within media designed in a target-group-specific way and tested by the target group, that might act as a starting point to analyse the previous findings’ inconsistencies. However, it is also this approach that questions most of the research’s findings so far - as e. g. the lack of background information to evaluate certain findings makes it mandatory to handle such research with care. So this thesis should be seen as an initial point - coupled with the call for a consideration of target-group-specificity within future research projects

The Impact of Target-Group-Specific Metaphorical Headlines on a Direct Mail’s Advertising Effect: An Exploratory Mixed Methods Approach.

Purpose of the Study This study’s purpose is to analyse the influence of a metaphor’s persuasive effects on a direct mail’s advertising effect - and by doing to so close a research gap, as until now research concerning the effects of metaphors used in promotional communication has been restricted to print advertising. State of Knowledge Even though theory suggests manifold effects of metaphors on recipients, the research conducted so far in this field of interest shows inconsistent results: although metaphors seem to be able to affect e. g. a recipient’s attention, attitude or behavioural intentions, the use of metaphors is by no means a warrantor for persuasive effects. The Approach of Tarqet-qroup-specificity On closer examination of the subject’s extant knowledge, the underlying research identified certain moderating variables that can be suggested to influence a metaphor’s effects on recipients. As most of the moderators can be assumed to be dependent on the underlying target group, the approach of target-group-specificity has come into existence - suggesting, that the findings’ inconsistencies result from the tested metaphors’ different levels of target-group-specificity. Furthermore, the approach of target-group-specificity has been expanded from the issue of metaphor to the test scenario as a whole: to test the advertising effect of a metaphor does not only imply to account for a metaphor’s moderators to become more relevant for the target group but also to embed this target-group-specific metaphor in a target-group-specific promotional communication, which is then evaluated by the underlying target group. Course of Action and Findings 1st stage: Qualitative Development of the target-group-specific Elements Firstly, the needed information to develop the target-group-specific metaphor, the product as well the mailing has been worked out within a qualitative focus group consisting of target group members. Furthermore, a qualitative approach was designed to develop metaphors with different levels of target-group-specificity. Here, a non-, a less- and a target-group-specific metaphor as well as a target-group-specific literal equivalent were defined. 2nd stage: Quantitative Testing of the variably specific Metaphors Secondly, three headlines consisting of the three qualitatively developed metaphors were quantitatively evaluated by the target group. The recipients rated the different headlines’ aptness to promote the product developed within the focus group and decided in favour of the target-group-specific metaphorical headline - with the less-and non-significant versions taking the second and third place. 3rd stage: Quantitative Testing of Mailings containing different Metaphors Thirdly, the three tested headlines as well as a fourth target-group-specific literal headline were included into a target-group-specific mailing. The target group evaluated the four different mailings concerning their advertising effect. Given this, the mailing containing the target-group-specific metaphorical headline took the leading position. However, the comparison of the other three mailings did not indicate any significant differences. Implications Hence, the research question can be answered in the affirmative: there is a difference between direct mails that use target-group-specific metaphorical headlines and those that use none concerning their advertising effect - as target-group-specific metaphorical headlines seem to increase a direct mail’s advertising effect compared to less specific metaphorical as well as target-group-specific literal headlines. However, next to the fact that this thesis closed a research gap by expanding metaphor research to the field of direct marketing, it becomes apparent that it also opens up a new research field by inventing the thesis’ fundamental basis: the approach of target-group-specificity. It is this approach, i. e. , the need for target-group-specific metaphors applied to target-group-specific products within media designed in a target-group-specific way and tested by the target group, that might act as a starting point to analyse the previous findings’ inconsistencies. However, it is also this approach that questions most of the research’s findings so far - as e. g. the lack of background information to evaluate certain findings makes it mandatory to handle such research with care. So this thesis should be seen as an initial point - coupled with the call for a consideration of target-group-specificity within future research projects

Caedibacter macronucleorum sp. nov., a Bacterium Inhabiting the Macronucleus of Paramecium duboscqui

The macronucleus of Paramecium duboscqui was observed to contain bacteria. Two morphologically different types of bacteria were found. Type 1 was 1.5-3.0 µm long and 0.5-0.8 µm wide. This type sometimes contained R bodies, which were associated with capsids of bacteriophages. The capability to producing R bodies was, however, lost in some host cell lines in laboratory culture. Type 2 had a length of 0.8 to 2.0 µm and a width of 0.4 µm, but sometimes occurred as much longer rods, which were straight, curved or crescent-shaped. Because of the morphological features of type 1 and of its ability to produce R bodies, the bacterium was named Caedibacter macronucleorum sp.n. Both types of bacteria were maintained by their host cells under all conditions tested. It cannot be decided, whether type 2 of the bacteria, which did not produce R bodies, represents a different stage or morph of the same species or belongs to a different species of bacteria. © 1993, Gustav Fischer Verlag Jena. All rights reserved