**EXHIBIT      31.2 **

**CERTIFICATION      PURSUANT TO SECTION 302**

**OF      THE SARBANES-OXLEY ACT OF 2002 **

2.    Based      on      my knowledge, this report does not contain any untrue statement of a material      fact or omit to state a material fact necessary to make the statements made,      in      light of the circumstances under which such statements were made, not misleading      with respect to the period covered by this report; 

3.    Based      on      my knowledge, the financial statements, and other financial information included      in this report, fairly present in all material respects the financial condition,      results of operations and cash flows of Sentra as of, and for, the periods      presented in this report; 

4.    Sentra’s      other certifying officer(s) and I are responsible for establishing and      maintaining disclosure controls and procedures (as defined in Exchange Act      Rules      13a-15(e) and 15d-15(e)) and internal control over financial reporting (as      defined in Exchange Act Rules 13a-15(f) and 15d-15(f)) for Sentra and have:      

a.    Designed      such disclosure controls and procedures, or caused such disclosure controls      and      procedures to be designed under our supervision, to ensure that material      information relating to Sentra, including its consolidated subsidiaries, is      made      known to us by others within those entities, particularly during the period      in      which this report is being prepared; 

b.    Designed      such internal control over financial reporting, or caused such internal control      over financial reporting to be designed under our supervision, to provide      reasonable assurance regarding the reliability of financial reporting and the      preparation of financial statements for external purposes in accordance with      generally accepted accounting principles; 

c.    Evaluated      the effectiveness of Sentra’s disclosure controls and procedures and presented      in this report our conclusions about the effectiveness of the disclosure      controls and procedures, as of the end of the period covered by this report      based on such evaluation; and 

d.    Disclosed      in this report any change in Sentra's internal control over financial reporting      that occurred during Sentra's most recent fiscal quarter (Sentra's fourth fiscal      quarter in the case of an annual report) that has materially affected, or is      reasonably likely to materially affect, Sentra's internal control over financial      reporting; and 

5.    Sentra's      other certifying officer(s) and I have disclosed, based on our most recent      evaluation of internal control over financial reporting, to Sentra's auditors      and the audit committee of Sentra's board of directors (or persons performing      the equivalent functions): 

a.    All      significant deficiencies and material weaknesses in the design or operation      of      internal control over financial reporting which are reasonably likely to      adversely affect Sentra's ability to record, process, summarize and report      financial information; and 

b.    Any      fraud, whether or not material, that involves management or other employees      who      have a significant role in Sentra's internal control over financial reporting.      

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| Signature: | /s/                  Bonnie Septimus |                                                          |   |   |
|------------|--------------------------------------|---------------------------------------------------------------|--------|--------|
|            | Name:                      | Bonnie                Septimus                                |   |   |  |
|       | Title:                     | Treasurer,                Secretary and Director              |   |   |   |
|       |                            | (Principal                  Financial and Accounting Officer) |   |   |   |

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